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
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
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!