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This keto lemon bar recipe features a foolproof shortbread crust atop a creamy, zesty lemon filling. They’re wildly refreshing and only 2 grams of net carbs per bar!
Want more lemony keto desserts? Try my keto lemon meringue pie, keto lemon curd, and keto lemon blueberry muffins next.
This may be controversial, but I often prefer lemon desserts over chocolate ones. When I’m watching my carbs, that means I make my low-carb lemon bars by the dozen.
The tangy, gooey lemon filling is complemented by the crisp shortbread crust, making for a balance of flavors and textures that rivals my traditional healthy lemon bars!
Table of Contents
Why I love this recipe
- They’re easy to make. Even if you’ve never made a lemon bar a day in your life, I promise you’ll have no trouble making these.
- Bursting with lemon flavor. This is for all you lemon lovers out there, especially those of us watching our carbs.
- 2 grams of net carbs. Oh, and they also happen to be gluten-free.
- Uses fresh OR bottled lemon juice. I prefer fresh juice, but when I don’t have any on hand, the bottled stuff works just as well.
★★★★★ REVIEW
“These are the best low-carb lemon bars I’ve ever made!” – Ellen
Ingredients needed
Here’s what you’ll need for the crust:
- Almond flour. This is used for the shortbread crust. Be sure to use blanched almond flour, not almond meal.
- Allulose. My preferred keto sweetener that dissolves just like sugar does. I’d recommend avoiding monk fruit sweetener as it can be grainy.
- Egg. Room temperature.
For the filling:
- Lemon juice AND zest. For the lemon flavor! I suggest using fresh lemon juice as we’ll also be using the zest.
- Egg. Again, use room temperature eggs. 6 eggs might seem like a lot, but trust me, it yields the most gooey filling ever.
- Allulose. For sweetness. Again, please do not use monk fruit sweetener or other keto sweeteners that don’t dissolve like sugar does.
How to make keto lemon bars
I’ve included step-by-step photos below to make this recipe easy to follow at home. For the full printable recipe instructions and ingredient quantities, scroll to the recipe card at the bottom of this post.
Step 1- Prep. Preheat the oven to 180C/350F and line an 8×8-inch baking dish with parchment paper.
Step 2- 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 3- Bake. Bake the crust for 15 minutes or until golden.
Step 4- Make the filling. Whisk the eggs together until no whites remain. Add the sugar, lemon juice, and lemon zest and continue whisking until smooth.
Step 5- 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 6- Cool and serve. Remove from the oven and let cool in the pan. Refrigerate for 2 hours. Once ready to serve, sprinkle with extra powdered sugar.
Arman’s recipe tips
- Keep an eye on the crust. You’ll add the lemon filling the second it’s done baking. This makes sure the filing remains thick and that 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.
- 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 bars should be stored in an airtight container in the refrigerator for up to two weeks.
To freeze: Place bars in a ziplock bag and store in the freezer for up to 6 months. Thaw in the refrigerator overnight.
More keto dessert recipes you’ll love
Keto Lemon Bars
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 * See notes
- 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
Nutrition
Originally published August 2020, updated and republished June 2024
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!