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
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?
I cannot have almond flour. Can you recomend a substitute.
Yes! Sunflower seed flour is an equal swap that will yield identical results 🙂 Let me know how you go!
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??
Hi Holly- sorry for not seeing this! Granulated allulose 🙂 And no butter- in testing, I found that it curdled with the lemon filling 🙂
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!