Keto Lemon Bars
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My keto lemon bar recipe features a foolproof shortbread crust atop a creamy, zesty lemon filling. They’re wildly refreshing and only 3 grams of net carbs per bar!
This might be controversial, but I often reach for lemon desserts over chocolate- especially when I’m trying to keep things lower carb (and my partner loves all things lemon). That’s precisely why I ended up making these low carb lemon bars a lot.
Keto lemon bars can be unforgiving. I went through several test rounds to find the sweet spot where the lemon filling stays gooey and rich, and the crust actually slices clean instead of falling apart (very common with keto desserts). What made the difference wasn’t one magic ingredient, but the balance of acidity, sweetness, and ample fat, so that nothing detracts from the lemon.
What’s left is a silky, tangy lemon filling over a crisp, shortbread-style crust that holds everything together. They are just as satisfying as my healthy lemon bars, and one of those recipes that even those who aren’t watching their carbs enjoy!
Table of Contents
Why make my keto lemon bars
- Quick and easy. All up, you need just five simple ingredients, and less than 40 minutes of bake time.
- 2 grams of net carbs. Oh, and they’re also gluten-free.
- No eggy flavor. My recipe does use plenty of eggs, but I promise you, you won’t taste them.
★★★★★ REVIEW
“These are the best low-carb lemon bars I’ve ever made!” – Ellen
Key Ingredients
Here’s what you’ll need to make my lemon bars, along with kitchen notes. The complete list with measurements is in the recipe card below.
- Shortbread crust. I’m using a combination of blanched almond flour, allulose, and a room-temperature egg.
- Lemon juice and lemon zest. I suggest using fresh lemon juice, as we’ll also be using the zest.
- Egg. 6 eggs might seem like a lot, but trust me, it yields the most gooey filling ever.
- Allulose. For sweetness. I tested nearly every keto sweetener on the market (monk fruit, erythritol, and even stevia), and allulose is the only one that dissolves like sugar and keeps the filling gooey and sweet, rather than gritty or granular.
How to make keto lemon bars
Step 1- Make the crust. In a large mixing bowl, combine the almond flour, allulose, and egg and mix well. Transfer the mixture to the lined pan and press into place.
Step 2- Bake. Bake the crust for 15 minutes or until golden.
Step 3- Make the filling. Whisk the eggs together until no whites remain. Add the remaining ingredients and continue whisking until smooth.
Step 4- Second bake. As soon as the crust is done baking, remove it from the oven and spread the filling on top. Bake the bars for 20-22 minutes or until the center is firm but jiggles slightly.
Step 5- Cool and serve. Remove from the oven and let cool in the pan. Refrigerate for 2 hours. Once ready to serve, sprinkle with extra keto powdered sugar.
Arman’s recipe tips
- Keep an eye on the crust. You’ll add the lemon filling as soon as it’s done baking. This ensures the filling remains thick and the eggs don’t separate.
- Don’t overbake the bars. They’ll continue to cook as they cool down and thicken more after they’ve been refrigerated (called carryover cooking).
- Add more lemon flavor. If you’re like me and prefer your lemon bars extra tart, add some lemon zest to the filling.
- Enhance the flavor of these sugar-free lemon bars by adding a pinch of salt or one teaspoon of vanilla extract.
Storage instructions
To store: Leftover lemon bars should be stored in an airtight container in the refrigerator for up to two weeks.
To freeze: Place leftover bars in a ziplock bag and store in the freezer for up to 6 months. Thaw in the refrigerator overnight.
✅ Nutrition reviewed
“These bars are a favorite recommendation for clients who miss citrusy treats. Replacing refined flour with almond flour increases fiber and keeps net carbs under 3 grams, making it a satisfying option that won’t send blood sugar soaring.” – Felicia Newell, MScAHN, RD, CPT.
Keto Lemon Bars
Video
Ingredients
For the shortbread crust
- 2 cups almond flour
- 3 tablespoons allulose
- 1 large egg
For the lemon filling
- 2/3 cup lemon juice
- 6 large eggs
- 2/3 cup allulose
- 1 teaspoon lemon zest
Instructions
- Preheat oven to 180C/350F. Line an 8 x 8-inch pan with parchment paper and set aside.
- In a mixing bowl, combine your almond flour, allulose and egg, and mix well. Transfer the mixture into the lined pan and press into place.
- Bake the shortbread crust for 15 minutes, or until golden. While it is baking, prepare your lemon filling.
- In a separate mixing bowl, whisk together the eggs until no whites remain. Add the lemon juice, allulose, and lemon zest and whisk until combined.
- Remove the shortbread crust from the oven. Moving quickly, add the lemon filling and smooth it out evenly.
- Bake for 20-22 minutes, or until the center is firm but still jiggles slightly.
- Remove from the oven and let cool in the pan completely, before refrigerating for at least 2 hours, to firm up more.
Notes
- Tips: See my recipe tips above for perfect keto lemon bars.
- Sweeteners: Please don’t substitute allulose- it’s the only sweetener I tried that didn’t leave the filling gritty or the shortbread crust crumbly.
- Leftovers: Keep in the fridge for up to two weeks or the freezer for up to 6 months.
Nutrition
More keto dessert recipes
- Keto fudge– Just two ingredients and so rich and creamy.
- Keto chocolate chip cookies– Classic, bakery-style with crisp edges and gooey middles.
- Keto peanut butter bars– If you love peanut butter and blondies, give these bars a go.
- Keto pound cake– I love this gorgeous pound cake with a coffee mid-morning.
Originally published August 2020
Delicious
Thank you Sheila, so glad you enjoyed these.
Nom. Loved how simple this crust was to make. For the filling, I ran the lemon juice up to 3/4 cup for more kapow and dropped the egg count to five for a softer texture. FAB.
YUM!
Looks delicious. I am trying to eat low sugar and carbs.
The filling fell flat. It isn’t thick and gooey like the pictures show. Should I whisk in my stand mixer? How do I get the filling to look like the pics? How do I get the filling to taste less eggy?
Crust was good and I’ll add salt next time.
I increased the lemon juice and allulose to 1 cup each and added 2 egg yolks to address the extra liquid. That sounds like it’d make it more eggy but it really didn’t. Mine were nice and lemony!
I made the Lemon bars, the 1st batch got me hooked. The 2nd batch, I changed the crust slightly though. Instead of 2c. Almond flour I used 1 3/4 c. almond and 1/4c coconut flour.added 1T. Truvia brown sugar and 1/4t. Salt. I liked the crust better that way. BUT I make it for the diabetic and low carb crowd at church breakfast. Both versions were a HIT. so thank you sooo much. I’m looking in to more , I have 3 recipies that have turned out. 😋
Very easy and yummy. Will definitely make again.
WAAAAY too many eggs, drop it down to 4
It was amazing! I added more zest, you can also double the filling recipe and make a keto pie crust , for a lemon pie.
I over-cooked it! Otherwise would have been GREAT! Love your website!
This turned out to be a soggy mess. A waste of 7 eggs and good lemons!
Outrageously good! Dare I say better than Grammie Jean Lou made but low carb, no sugar and gluten free?
Gorgeous recipe, just needs salt. I have made it a couple times now and it is a hit!
These are my favorite keto lemon bars EVER!
These keto lemon bars are amazing!! You would never know they don’t have white sugar or wheat flour. I will definately be making these more often.
These lemon bars are very good. My only criticism is that the crust needs salt! It is very bland and takes away from the delicious filling. The second time I made them I added a rounded 1/4 tsp salt to the crust and added 4 oz of cream cheese to the filling. I blended softened cream cheese with the allulose until smooth and then proceeded with the rest of the ingredients. They are DELICIOUS! I will definitely make these again with and without the cream cheese.
These were great ! Nice and tart like a lemon slice should be not eggy .. Im in aus I used lakanto brand brown monk fruit sweetener it melts in fine – I did notice my slice is more caramel in colour not like ur vibrant yellow slice but I’m still happy thanks I’ll def make this again
I tried to find allulose but cannot find it anywhere. You have reccomendation?
Hi Arman,
As a fellow Australian, where do you get your allulose? Do you need to buy it online from the US? It is super expensive to do that. Would Natvia or Xylitol be OK replacements? Any info would be greatly appreciated.
Hi Jeanette- I do get it from overseas. Unfortunately natvia and xylitol will yield a gritty texture.
I used monkfruit powdered sweetener for the filling and it dissolved perfectly. My husband thinks these are even better than regular (non-keto) lemon bars!
Love that!!!
Interesting recipe. I just dont know where to buy allulose. I dont actually know what even is.
I found it cheapest at Walgreens
Many of your keto recipes have almond flour. To be honest I like carbs and feel so much better eating them haha.
This recipe is just amazing! Love the lemon flavour. If I wanted to make them for a larger group and not keto what flour do you suggest I use?
Plan to try these since I’m serious about Keto right now, I also prefer allulose, and they sound great.
However, I have a question: Why does it say “buttery” crust when there’s no butter in the recipe? I love the taste of butter should I put some in the crust instead of the egg?
Thanks for all the effort you put into your excellent recipes.
It’s naturally buttery because of the almond flour 🙂
Delicious. I have to eat gluten and dairy free so I find that keto recipes work well for me as they typically don’t have either ingredient. These were so great they tasted like lemon meringue pie. I was so happy with them. Definitely a do over. I used monk fruit and it worked great as a sweetener.
Arman, are you calling for powdered allulose here or liquid? also, no butter in the recipe??
Hello-
I’d like to try your recipe but in place of coconut flour could I use almond flour instead? Thank you.
You could try. I’ve only made it as written!
Your recipe sounds good.will try it. thanks
This is the best keto lemon bar recipe EVER!
Fantastic recipe
These lemon bars are TOO good!
Can I use powdered allulose?
You could try!
The crust delicious, the lemon curd fabulous. Not as pretty as your pic but OMG! I’m in love
If anybody has made these and used something besides coconut flour that worked well & stayed in the low-carb zone, let me know! My husband has a coconut allergy. 😢
For those of you having trouble with curdling. If you haven’t tried this already, make sure all of your wet ingredients are room temperature. That should help with curdling. Hope this is helpful.
these are the best low carb lemon bars I’ve ever made!
I tried to make this but, after 2 attempts I can’t get it to mix up and not curdle my butter
Donna, It’s likely happened to everyone. I wrote Arman but didn’t get a reply. I asked if you could cream the butter with the sugar first and then add the lemon juice slowly. After that, follow with the eggs. I added 1/2 tsp of vanilla too at this point. I added a little sea salt (1/4 tsp) to the shortbread and lemon filling. I’m going to try it one day. Regardless, they came out great even though the butter curdled so to speak. Everything else was on point.
Very good! I cheated a little and put everything in the blender on low to stir and poured on base after just 13 minutes (convection oven always does things quicker it seems) and did the last bit just just 15 minutes of baking.
Tasted this while still warm after sitting for 1/2 hour and quit nice warm. The chilled version certainly firms it up more.
I made the lemon bar recipe and went exactly by it The recipe and when the bar’s cooled in the fridge long enough, I tried one it was wonderful. But the next day I tried another and the sugar had gone gritty I don’t know what I did wrong but I’m disappointed they were so good I hope you can tell me where I went wrong. Looking forward to your help thank you.
Your my go too!!! When it comes to all my keto recipes!!! When will your cookbook be available? Thanks for all your delicious recipes!
1st, I highly recommend these, thank you for the recipe, it made delicious Lemon Bars!! 2nd, I made them in an air fryer!
My notes on the Bars (not negatives – just preferences going forward):
1. There is quite a lot of butter in the crust, and while yummy, and it did set, I prefer a dryer shortbread bottom. I used Bobs Super Fine Almond Flour. When I make again, I might either use a little less butter, or add a tbsp of coconut flour to try to off set that. Shredded coconut in the crust would be good too…hmm.
2. I added the zest of 1 Lg Lemon to the crust, and zest of 1 Lg lemon to the custard. I am glad I did, most lemon desserts are never “lemony” enough for me 🙂
3. These are super rich, with all the butter and eggs, so I cut into small bite size squares, so in turn, this recipe made a lot for me. I am freezing half!
Notes on Airfryer, for anyone curious (as I was, and had to research):
1. I have a Gowise oven/air fryer. Between it being summer, and gas prices, running my oven just doesn’t make good sense. I literally got it 3 days ago, and these bars were my first experiment! So far so good.
2. I put a rack in the middle of the oven. This oven has a “dual heating element”. You can use one, or both. I turned both on.
3. I used an 8×8 pan, parchment lined, no need to grease pan, it has a lot of butter in it
4. I preheated the air fryer to 320 F
5. I baked the crust at 320 for 10 min, and it was golden brown. Probably could have taken out closer to 9 minutes, but ovens vary, so Id start watching at 7 minutes
6. Once I added the custard, I baked again at 320, for 14 minutes. Checked at 12min, and it was a little to jiggly in the middle.
Really good, glad I found you, and looking forward to trying more of your recipes, they look and sound so good.
You mentioned there’s a lot of butter in the crust, but there is no butter in the recipe. I’m so confused because I’ve never seen a lemon bar crust without butter….help!
Hi Holly- sorry it was an error 🙂
Will almond flour work in place of the coconut flour?
Not for this!
Can I substitute almond flour for the coconut flour (my store didn’t have any)
Nope! Won’t work.
I’ve made this several times and had the same results. turned out fine even though the butter separated. I found if I drizzled the lemon juice into the creamed butter and sugar very slowly while whipping, the butter didn’t separate.
Made these for an Easter dessert for keto peeps. Easy recipe, very tasty and refreshing. Satisfying and rich. I will make them again but I will cut back on crust as for me it was a bit thick. Perfect refreshing lemony treat!!!! Thanks for this great recipe
How do I get to the glossy part? Made these two times now with the butter room temp and the lemon juice room temp. The butter always chunks up. I ended up microwaving the mixture so it could all be mixed together. They tasted amazing! I added zest and increased the lemon juice to 3/4 cup, though. 🙂 Still confused about the butter and juice. Thank you for this delicious recipe!
These were actually fantastic. You can barely tell that they are keto. For me the consistency was a touch off, probably would have been better with a powdered substitute but all I had was regular eryrithrol. Regardless, they were quite delicious, even with the slight graininess of the eryrithrol. If you’re trying to find a good keto dessert that doesn’t have a ton of carbs, and is actually good I highly recommend giving this recipe a try. I also recommend patiece with this recipe they take forever to cool.
These were good but need salt in the recipe to bring out more flavor plus I added vanilla extract to both parts .
This is YUMMY. So I made it lighter in calories by using 4 egg whites and 2 whole eggs. No need for powdered sugar on top, it is perfectly balanced in sweetness as is. Thanks!
Well, I did try it and it was a disaster. I followed your recipe and instructions precisly. as soon as I took the crust out when it was golden brown, I poured the lemon mixture over it and the crust fell apart and the lemon mixture went under the crust batter. Perhaps I would have needed to wait for the batter to settle or cool to firm up, but who knows.
I think if you let the crust cool before adding the lemon custard topping, it will work fine with coconut oil.
Can I use cold-pressed coconut oil instead of the butter and if so, the same amount as the butter?
Not sure, I’ve only tried this as written
These are soo good! In fact, all of your recipes that I have tried are since i have been on Keto, thank you SO much.
I made the mistake of letting my butter warm but forgot to let the lemon juice come to room temp, so my butter seized; therefore, I never got to the glossy part of the instructions. The filling was all liquid so I added another tablespoon of coconut flour and the end result was great. I really loved the shortbread crust too!
These are delicious in spite of my mistakes! I have made them twice but the melted butter clumps when I add it to the eggs,lemon juice powdered sugar (I use Swerve Confectioners) and coconut flour. I had the eggs sitting out to room temp a full day. Even made sure the lemon juice was room temp. But still the soften butter clumped. Did anyone else have this problem?
Hi Arman, I’m looking forward to making these. Are the measurements US cup sizes or Australian/Metric? Does it make a difference as the cup sizes are different?
Thank you, H.
US cups 🙂
I only had to cook the custard for 15 minutes (altitude?), but these are phenomenal! I used Allulose (no aftertaste!) that I powdered in a coffee grinder and I added 1/3 cup unsweetened coconut to the shortbread. If I hadn’t made them myself, I’d never believe they’re keto! Thank you for this amazing recipe!
Aw, cheers, Sabrina!
Omg, soo good! My 3 years keto husband, and even my 14 year old daughter and her friends loved them.
I have tips for others, though.
Powdered erythritol is expensive, but I have found that it powders easily in the coffee grinder.
It took exactly 3 huge lemons to make these.
I doubled it and used a 9×13 pan and ended up doubling the crust baking time, and the crust turned out perfect
Thank you, Michelle!
Arman, do you have a Keto diet plan available?
No I do not 🙂 But sharing a new cookbook soon!
Pretty darn good. My daughter even liked it.
😀 Fabulous!
Can I not use coconut flour?
This recipe only works as written.
Wow just made this for my daughter and I and we love it! Thank you!
🙂 So welcome!
These were amazing!
Never Mind my question about replacing eggs. I just found it.
to make these vegan, would I use aguafabe or egg replacer? I didn’t see it in the notes. Thanks! Looking forward to trying these recipes!
Absolutely yummy and so easy to make! Hard not to eat the entire pan myself. Adding lemon zest definitely gives it a wonderful bit of zing. I have another pan in the oven right now!