Fresh and tangy keto lemon bars, drizzled with lemon juice and lemon zest, are only 2g net carbs per serving.
One-bowl keto lemon bars recipe is quick and easy. Serve them sprinkled with powdered sugar-free sweetener.
These keto lemon desserts are made with gluten-free coconut flour, melted butter, eggs, and lemon juice so these sugar-free lemon bars can be enjoyed guilt-free!
My entire family is pretty obsessed with lemon desserts like this one-minute lemon mug cake and my sugar-free no-bake lemon cheesecake.
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What are keto lemon bars?
Keto lemon bars are wonderfully zingy baked cake bars that are sugar-free, gluten-free, and lower carb.
They’re fabulous to pack in school lunch boxes because they are sturdy, yet still soft like regular cake and have that wonderful lemon zest taste.
Top the keto lemon bars with a sugar-free syrup made with lemon juice and powdered sugar-free sweetener.
With only 2g net carbs per bar, these low-carb lemon bars will easily fit into your low-carb diet or keto diet.
Ingredients
- Butter – you can use salted butter or unsalted butter (with a pinch of salt). Make your cake batter with softened butter or melted butter.
- Granulated and powdered sweeteners of choice – the most popular sugar-free sweeteners are erythritol, stevia, allulose, monk fruit, and xylitol.
- Eggs – always use fresh eggs, medium size.
- Coconut flour – coconut flour is a naturally gluten-free flour that you can use in many more keto dessert recipes.
- Almond flour – almond meal works well too. Almond flour is another naturally gluten-free flour and low-carb flour.
- Natural yogurt – look for a full-fat, unsweetened yogurt for this keto lemon bar recipe.
- fresh lemon juice – fresh juice is best, but feel free to use bottled lemon juice.
- lemon zest – fresh lemon zest is tangy and delicious, but you can use freeze-dried lemon zest instead.
- vanilla extract – or vanilla extract.
Get the full instructions and amounts in the keto lemon bars recipe card below. These easy keto lemon bars yield 10 servings.
Instructions
It’s so easy to make the best keto lemon bars. In fact, they are so simple that you can add this sugar-free lemon bars recipe to your weekly meal prep.
These lemon bars resemble a cake and have a combination of almond flour and coconut flour that makes them soft and pillowy. Here’s how to make them!
So if you want a sweet treat that’s sugar-free, this amazing recipe is packed with lemon flavor and is one of those easy keto recipes you will come back to time and time again.
Mix the batter
In a large mixing bowl, cream together the melted butter and sugar-free sweetener until it is pale and fluffy.
Add eggs. It may resemble curdles but don’t worry. The next step will bring the batter together.
Fold in the coconut flour and almond flour.
Next, gently add the yogurt, vanilla extract, fresh lemon juice, and lemon zest.
Mix until the keto lemon cake batter is smooth.
Bake the bars
Pour the keto cake batter into a rectangle baking dish that has been oiled and lined with baking parchment paper.
Bake the low-carb lemon bars at 180C/350F for 15-20 minutes, or until baked in the center. They don’t need to be golden brown, just baked through.
Make the lemon drizzle
Mix lemon juice (or bottled lemon juice) with the low-carb sweetener in a small mixing bowl until it is completely dissolved. the easiest sweetener to use is powdered erythritol. It tastes just like sugar and dissolves easier.
Add drizzle on top of lemon bars
Add the sweetened lemon juice to the low-carb lemon bars while they are still warm in the baking pan. Pour slowly over the top of the keto lemon cake or drizzle with a large spoon.
To ensure the juice is soaked up by the lemon bars, you can poke holes all over the top with a fork.
Cut the lemon bars into individual pieces (squares or rectangle lemon bars) and serve.
Storage
Remember when I said these were great for meal prep? You can freeze lemon bars and enjoy them six months from now. To do so, let the bars cool completely to room temperature on a wire cooling rack, then place them in an airtight container, and freeze.
Tip: You can add a bit of parchment paper in between each layer of bars so they don’t get stuck together.
Substitutions
If you don’t have fresh lemon juice, you can use jarred lemon juice or bottled lemon juice. I often have frozen lemon juice I made from fresh lemons from my tree.
Sometimes you can use almond meal instead of almond flour, but in this recipe, I suggest just using almond flour. This is because almond flour has a smoother texture to it.
When you make sugar-free lemon bars with almond flour they will resemble a classic cake.
Variations
These are the best keto lemon bars, but you can also create your own variations on the recipe. Here are a few ideas to try:
- Make keto lemon muffins. Instead of low-carb lemon bars, you can place the mixture into a muffin tin and muffins. This recipe is one of my favorite keto lemon desserts because it is so fresh and fillings.
- Sprinkle on some “sugar”. Sprinkle some powdered sugar substitute on top for a fun topping. You can use granulated sweetener for a crunchy topping or powdered sweetener to look like confectioners sugar.
- Adjust the flavor. Make the lemon filling as sweet or as tart as you want by adjusting how much sweetener you used. If you don’t like too much lemon, you can omit the lemon zest.
- Add a lemon filling. Make some sugar-free lemon curd (keto lemon curd) and spoon some into the center of keto lemon muffins, or spread over the top of a keto lemon cake.
Top tips
How much sweetener to use
Lemons vary considerably in their sweetness, sour taste, and depth of zest. So the amount of sweetener I suggest may need to be adjusted when you make keto dessert recipes. Always add the minimum amount of sweetener then add more for your favorite sugar replacement until you reach the desired sweetness.
Which sweetener is best?
It may take some trial and error to find a low-carb or keto sweetener that you really love to use. If you are a beginner, you need to read the Ultimate Guide to Sweeteners.
Some sweeteners such as stevia need to be added very slowly. This is because stevia has a bitter aftertaste if you use an excessive amount.
Some sugar alcohols give you a slight cooling effect in the mouth.
Whichever sugar replacement you use, check to see if it affects your blood sugars. While most do not have any effect, some, such as maltitol, do raise blood sugar, so stay away from those.
🍋 Recipe FAQs
Here are some questions people often ask about how to make this keto lemon bar recipe. If you don’t see your question in this list, please leave it in the comments.
Yes, lemon is a keto-friendly fruit. There are 3.7 grams of net carbs in one lemon and there is only a small amount of lemon in each portion.
They are probably gooey because the lemon filling didn’t bake all the way. Keep it in the oven for a little bit longer.
Yes, you should refrigerate the keto lemon bars. They need to be covered if you are going to store them in the fridge to stop them from drying out.
You will know they are done if you stick a toothpick in the middle and it comes out clean.
Yes, these keto lemon bars are made with two low-carb flours – coconut flour and almond flour, making them naturally gluten-free.
You could make these keto lemon bars keto orange bars instead. Use fresh orange juice and orange zest instead of lemon zest. The flavor will be subtle but delicate. It’s a fantastic recipe if you don;t like too much lemon flavor’
No, both these gluten-free flours are required to make keto lemon bars soft and fluffy. Coconut flour and almond flour both have different properties and cannot be easily swapped.
Yes, pop them (sliced) in the freezer in an airtight container (or a ziplock bag) for up to 3 months. You can defrost each of the keto lemon bars one at a time on the kitchen bench at room temperature for 1-2 hours.
Yes, this lemon bar recipe is the easiest keto lemon dessert recipe. It doesn’t need an almond flour shortbread crust, lemon filling, or lemon curd. These low-carb lemon bars are all made in one large mixing bowl then baked.
Keep egg yolks and make sugar-free lemon curd.
Use egg whites to make a keto meringue roulade.
No, the butter is what gives these keto lemon bars their amazing buttery and tasty flavor.
This recipe is definitely keto with only 2g net carbs per serving.
Keto Lemon Bars Recipe (Keto Lemon Cake)
Equipment
- Measuring cups and spoons
- Mixing bowls
- Parchment Paper
Ingredients
Sugar free lemon bars
- 110 g butter softened
- 4 tbsp granulated sweetener of choice or more, to taste
- 4 eggs – medium
- 24 g coconut flour
- 50 g almond meal/flour
- 80 ml natural unsweetened yoghurt unsweetened
- pinch salt to taste
- 2 tbsp lemon juice
- 1 tbsp lemon zest
- 1 tsp vanilla extract
Lemon drizzle
- 3 tbsp lemon juice
- 4 tbsp powdered sweetener or more, to taste
Instructions
Sugar free lemon bars
- Cream the softened butter and sweetener until pale and fluffy.
- Slowly add the eggs one at a time, mixing well before adding the next egg.
- Fold in the coconut flour and almond flour/meal.
- Fold in the yogurt, vanilla, lemon juice, and lemon zest. Stir gently until thoroughly mixed.
- Pour into a greased lined baking dish and bake at 180C/350F for 15-20 minutes, or until baked in the center.
- While the keto lemon bars are still warm (but not hot) slowly pour over the fresh lemon drizzle before cutting them into slices or squares.
Lemon drizzle
- In a small glass, mix the fresh lemon juice and the sugar-free sweetener until dissolved. It won't dissolve completely, but make sure there are no lumps.
- Drizzle/spoon the sweetened lemon juice over the warm sugar-free lemon bars. You can poke the keto lemon cake with a fork to allow the drizzle to really sink into the middle of the cake.
- Cut into slices/bars once it is cold and the lemon drizzle has soaked in.
Nutrition
If you love keto lemon bars you’ll love these keto desserts.
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What size baking pan?
Pictures below recipe show a 9 x 9″ pan.
Sounds good. What size pan?
Gosh I cant remember and now my kitchen is packed up for my renovation so I can’t go and measure for you. I do remember it was my ceramic rectangle baking dish. It was a medium size which allowed my to cut the tray down the centre then 5 rows across (hence it making 10 bars).
Hi all. I have just made this and is smells devine but I am struggling with tin size also. I have used a square medium baking tin but it has only risen barely 1/2″. Is this right? The photo shows a proper piece of cake. Should I be using a smaller tin?
Hmm, the eggs alone should make the cake rise more than that.
The same thing happened with mine, only rose about 1/2″, however it tasted great.
Is almond flour the same as ground almonds? I’m in the UK
Almond meal and ground almonds are the same thing. Almond flour is finer and has no almond skins in the mix.
Made these yesterday and they’re delicious.
Easy and delicious recipe! I’ve tried quite a few low carb dessert recipes from other sites and they never live up to expectations or even turn out like the picture. But this recipe is perfect! So delicious and satisfies that 3pm snack desire. My blood sugars didn’t spike at all (I have type 1 diabetes), I used Natvia for sweetener. Will be making again and will definitely use this as my go-to recipe site 🙂
Kirsty that is such a lovely review to read today, thank you so much and I’m glad you loved the lemon bars and the other recipes you are finding here.
Loved this recipe, so easy to make and rose up nicely, will be making again. Another great one for the Christmas table. Thank you for so many great recipes.
This is the first recipe I have tried from your website. Perfect! Easy & delicious! I’ll be trying more of your recipes soon. Thanks!
Can’t have nuts, how can I substitute?
If you can tolerate coconut flour, maybe try my flourless berry sponge?
No baking powder?
Libby – just checking because I made it too and it did not rise at all. It was delicious but seems other recipes do have some baking powder so just wondering? J
I don’t use baking powder in this recipe as I like the bars to be slightly dense, rather than cake like, and the eggs should make it light enough. Saying that, feel free to add baking powder of you would like them a little risen. 🙂
Where does the vanilla come into play?
I’ve amended it to make it clearer. It is added with the yoghurt, lemon etc.
Is there any chance you could clarify the size of the baking tin for this please? Thanks
Thanks for the beautiful recipe Libby! It’s so beautifully soft and delicious. I love lemon in anything and it’s fantastic to find a spectacular low carb recipe I will use over and over again. So easy to make as well. Thank you so much!
Wow Maureen, I am delighted you love these. Enjoy 🙂
These were great! Nice and moist and lemony. I only used 2 tbsp of Natvia in the mix and 3 tbsp in the lemon drizzle and that was sweet enough for me. I might actually use less sweetener in the drizzle next time or heat the lemon juice a bit so that it dissolves better. I used a 9 inch square pan but you could use a smaller one or add baking powder if you want them thicker.
I am allergic to nuts, so I can’t use almond flour. Can I just increase the coconut flour or should I look at another flour option to substitute for the almonds?
You might want to read my article “Coconut flour vs almond flour”. There is no easy substitution as you also have to vary the liquid quantities and number of eggs, so I would look at my cakes I already have developed using coconut flour – raspberry fingers, keto waffles for example. this one might be a bit tricky to adapt.
When I copied recipe link over into my fitness pal it told me the carb value was 10.6 grams dietary fiber is 6.3 meaning it’s 4.3grams of net carbs? It’s saying carbs of which sugars is 1.2 g do I subtract that too? I don’t usually make anything like this on keto. Also saying that calorie value was 255?
I have stopped trusting MFP years ago. Their values are so inaccurate as many are “user added”. In addition, some countries use total or net carbs and it is not clear which are represented. I use cronometer.com which is the most accurate database.
I just made these, and I have to say that these are beyond amazing. They’re so moist, and the lemon glaze takes this to a whole other dimension. Thank you so much for sharing!
What a lovely review, thank you 🙂
I’m making this to take on a camping trip. My confusion is exactly what size pan are you using? Thank You, can’t wait to try it. Sounds so good.
This would be superb for a camping trip, and my raspberry fingers too. From memory I used my 20cmx20cm pan.
A delicious recipe, and so simple – thank you! I find that lemon works really well with stevia, will definitely be making these again. Took me less half an hour to make these, perfect.
The cake was wonderful! But I managed to ruin it by accidentally using Pyure Organic Stevia EXTRACT powdered sweetener, which is insanely sweet. I only used 1 tbsp and mixed it with the lemon juice and it was too sweet. I thought it might be OK once it got into the cake.. and it wasn’t. Don’t make the same mistake as me!!
Oh dear. That is exactly why I don’t use the pure stevia products, too much room for error. You can always add more sweetener, you can never take it out. I hope you managed to salvage it somehow.
This shouldn’t happen, low carb recipe or not. Did you add the eggs one at a time and mix well? It should create lovely creamy batter.
The same thing happened to me. I creamed the butter and sugar and then added the eggs one at a time, mixing well everytime, but I still ended up with a “scrambled” look to it. Any ideas as to what might have gone wrong? The eggs were at room temperature.
Mine occasionally turns out like this, but it always seems to bake perfectly.
Has anyone tried this with coconut yogurt? Or another dairy free option.
I made it today and its fantastic!!! Thank you for sharing!!! They are so good. I used a 9×9 glass pan took a little longer to bake. So good!!!
will oil work instead of butter as I am dairy free 🙂
I am sorry but I have never used oil in this recipe so can’t say whether it would work or not, but I think it would change the texture and flavour. Can you tolerate ghee? Many readers who are dairy free can enjoy clarified ghee. Alternatively, try using coconut oil but you may have to add a pinch of salt and other flavours because the butter gives a creamy buttery punch.
Hi just wanted to ask about the sweetener. I have stevia but it very sweet so I don’t use it. I notice your using a different type. I was under the impression that artifical sweeteners weren’t good for you. Is this true?
I use stevia and/or erythritol, both of which are natural (even though they may not sound natural). They is a good post to read “The Ultimate Guide To Sweeteners” where I explain what I use and what I don’t. Which ones raise blood glucose, and which ones don’t.
Oh dear, lemon scrambled egg. Tastes ok – I love lemon so even bought really good quality ones for the bake BUT made the mistake of not reading the reviews. Such a disappointment after looking forward to it so much
I’m sorry to hear this Suzanne, did you use fresh coconut flour (and not desiccated coconut)? I use this recipe all the time and it never fails. Let’s see if we can figure out what went wrong.
I added baking powder because I thought I had written the recipe down wrong. Never made cakes without it, does it matter?
It will be fine if you added some baking powder, the eggs in this recipe should however, be enough to ensure it rises 🙂
Made these today! Sooo delicious. My seven year old son loves it. Thank you for sharing!
Excellent! I love it when kids enjoy new healthy recipes here 🙂
Wow – I made them a copule of weeks ago to bring them along at a function where we all shared some desserts . They all loved my Lemopn Squares (I made them like small squares perfect size…. so they turn out to be more and everybody could try ?), I replaced the yogurt with sourcream, they were just amazing! Thank you for this great recepie! Greetings from south of Switzerland
Brilliant Nicole! What lucky friends you have that you bake for them. Greetings from NZ 🙂
can I use all purpose flour instead of the coconut flour and almond meal flour?
Sorry no. It won’t be low-carb and grain free and these flours all work in completely different ways. You may wish to read this article. Ultimate Guide To Low-carb Flours.
Could the coconut flour be substituted for more almond flour?
It sounds like your coconut flour wasn’t behaving properly 🙁 Various brands can behave quite differently from one another and their ability to make a decent cake batter can depend on the humidity in the air. More coconut flour may sometimes need to be added to ensure a proper cake batter consistency. Don’t give up, just get great coconut flour.
I have been baking cakes for years and years. I promised a friend who is followings keto, that I was attempt a cake for her. We decided on this one. For some reason, I’ve fallen at the first hurdle and my batter split before I even got to add the flours. Normally, I would add some of the ordinary flour to bring it back but adding the coconut and almond mix didn’t work. I googled it and it said to go ahead and complete the batter. Against my better judgement, I stuck it in the oven. I too have ended up with an omelette, with melted butter all around the slab. Could it be the sugar substitute that made the batter curdle? I’m reluctant to try again, these ingredients are not cheap to keep throwing away. Would welcome any help and tips
not sure where i am going wrong, My cake always comes out too wet, i have removed one egg and used less yoghurt yet its still too wet?
It sounds like the brand of coconut flour may be affecting the cake batter. If there is too much humidity in the air or the brand hasn’t been dehydrated correctly, it will affect how much moisture the coconut flour can absorb. Next time, add an extra tablespoon at a time of coconut flour and almond flour. I’m sure it will thicken. Sometimes these new flours (which aren’t standardised) need a bit of experimentation to get them just right.
Me too! It didn’t rise, so I put one square on top of another, sandwiched with sugar free butter cream, and I think I got away with it, but maybe there should’ve been some raising agent in there?
I made this today. Mmmmmmmm with some whipped cream
Hi Debbie. I’m sorry to read this, let me help and see where it went wrong. Did you add enough sweetener? Did you add enough lemon zest and juice? Did you use coconut flour? The reason I ask is that some readers think desiccated coconut can be used but they both work in completely different ways. This is super popular bars and it can be made as cupcakes also so I think something went awry with the ingredients.
What size baking pan is recommended?
Hi Patti, I used a 7×11-inch pan. However, I have also used a 9×9 and 8×8 pan before. When using a smaller pan the bars will be thicker and may need to cook longer.