Keto Lemon Bars
Jump to...
Introduction
This post was originally published in partnership with Lakanto. We are no longer affiliated with them, and the opinions here are, as always, our own.
Sweet and tangy at the same time — that is what lemon bars are for. These are the one-bowl kind: buttery and soft set rather than a pressed crust under a separate curd, which is most of why they are quick enough to be worth making on a weeknight.
One of our all-time favorite desserts is Keto Lemon Pound Cake — moist, zesty, and drizzled with sweet icing. These lemon bars scratch the same itch with a lot less work.
Keto Lemon Bars Made With Lakanto’s Monk Fruit Sweetener
The whole recipe leans on two things: almond flour and real lemons.
Almond flour stands in for wheat flour here, and because it is all one batter rather than a base under a separate filling, there is no blind-baking step to get wrong.
Fresh lemon juice and zest carry the flavor. Bottled juice will work, and the bars will still taste good, but fresh juice is brighter, and you need a lemon in hand for the zest anyway. Two lemons give you both.
Two forms of Lakanto’s monk fruit sweetener do two different jobs. The granular goes in the batter, where it has butter and eggs to dissolve into. The powdered is for dusting the cooled bars, because granular crystals sit on top and stay gritty. If you are working out which product you actually have, Is Monk Fruit Keto-Friendly? explains how the forms differ and when one can stand in for another.
How to Make Keto Lemon Bars
The recipe card below has the full method, and there is not much of it: one bowl, one 9×9 dish. The parts worth slowing down for come at the end.
“Cooked through” means the middle no longer wobbles when you nudge the dish, so check for that rather than trusting the timer alone.
Then let them cool to room temperature before cutting; warm bars will not slice cleanly. Save the powdered sweetener for just before serving.
Storing Keto Lemon Bars
Keep leftovers in an airtight container in the refrigerator. Laying a paper towel over the bars before you put the lid on catches the condensation that would otherwise soften them.
Eat them within about four days. This is an egg-set bake, so the refrigerator is where it belongs rather than the counter.
They freeze too. Lay them in a single layer until solid before you stack or bag them, so they don’t fuse together, and thaw them in the refrigerator rather than on the counter.
Keto Lemon Bars
5 net carbsIngredients
- 2 cups almond flour
- 1 tsp vanilla extract
- ½ cup lakanto classic monkfruit sweetener
- 8 tbsp butter, unsalted, melted
- 3x large egg
- 2x lemon, juiced
- 1 tbsp lemon zest
- A pinch of lakanto powdered monkfruit sweetener, for dusting
Nutrition Facts
9 servings per recipe| Per Serving 270 | Per Recipe 2470 | |||
| 2 cups of almond flour | 160 | 1440 | ||
| 1 tsp of vanilla extract | 1.33 | 12 | ||
| 8 tbsp of butter, unsalted | 88.89 | 800 | ||
| 3x large egg | 20 | 180 | ||
| 2x lemon | 3.78 | 34 | ||
| 1 tbsp of lemon zest | 0.33 | 3 | ||
| 25g | 33% | 228g | 293% | |
| 2 cups of almond flour | 14.22 g | 128 g | ||
| 8 tbsp of butter, unsalted | 9.78 g | 88 g | ||
| 3x large egg | 1.33 g | 12 g | ||
| 2x lemon | 0.04 g | 0.4 g | ||
| 8g | 38% | 68g | 342% | |
| 2 cups of almond flour | 0.89 g | 8 g | ||
| 8 tbsp of butter, unsalted | 6.22 g | 56 g | ||
| 3x large egg | 0.5 g | 4.5 g | ||
| Trans Fat | 0g | 0% | 0g | 0% |
| 97mg | 32% | 870mg | 290% | |
| 8 tbsp of butter, unsalted | 26.67 mg | 240 mg | ||
| 3x large egg | 70 mg | 630 mg | ||
| 25mg | 1% | 210mg | 9% | |
| 1 tsp of vanilla extract | 0.04 mg | 0.4 mg | ||
| 3x large egg | 23.33 mg | 210 mg | ||
| 2x lemon | 0.22 mg | 2 mg | ||
| 18g | 6% | 159g | 58% | |
| 2 cups of almond flour | 5.33 g | 48 g | ||
| 1 tsp of vanilla extract | 0.06 g | 0.5 g | ||
| ½ cup of lakanto classic monkfruit sweetener | 10.67 g | 96 g | ||
| 3x large egg | 0.33 g | 2.97 g | ||
| 2x lemon | 1.2 g | 10.8 g | ||
| 1 tbsp of lemon zest | 0.11 g | 1 g | ||
| 2g | 8% | 20g | 71% | |
| 2 cups of almond flour | 1.78 g | 16 g | ||
| 2x lemon | 0.36 g | 3.2 g | ||
| 1 tbsp of lemon zest | 0.07 g | 0.6 g | ||
| 2g | 20g | |||
| 2 cups of almond flour | 1.78 g | 16 g | ||
| 1 tsp of vanilla extract | 0.06 g | 0.5 g | ||
| 2x lemon | 0.33 g | 3 g | ||
| 1 tbsp of lemon zest | 0.03 g | 0.3 g | ||
| 11g | 96g | |||
| ½ cup of lakanto classic monkfruit sweetener | 10.67 g | 96 g | ||
| Allulose | 0g | 0% | 0g | 0% |
| 5g | 43g | |||
| 2 cups of almond flour | 3.56 g | 32 g | ||
| 1 tsp of vanilla extract | 0.06 g | 0.5 g | ||
| 3x large egg | 0.33 g | 2.97 g | ||
| 2x lemon | 0.84 g | 7.6 g | ||
| 1 tbsp of lemon zest | 0.04 g | 0.4 g | ||
| 7g | 15% | 67g | 135% | |
| 2 cups of almond flour | 5.33 g | 48 g | ||
| 3x large egg | 2 g | 18 g | ||
| 2x lemon | 0.13 g | 1.2 g | ||
| 1 tbsp of lemon zest | 0.01 g | 0.1 g | ||
About these numbers: We are home cooks, not certified nutritionists. Nutrition is shared as a courtesy. We pick a representative product for each ingredient, and our recipe system works out the totals from the amounts in this recipe, so please treat them as a helpful estimate rather than a guarantee. The brands you buy, any swaps you make, and how generously you portion the recipe will all move these numbers.
Directions
-
Preheat the oven to 350F.
-
Place everything except the powdered sweetener into a mixing bowl, and beat on high until smooth.
-
-
Spread the mixture into a 9x9 baking dish.
-
-
Bake for 25-30 minutes until cooked through.
-
Let cool to room temperature, and then dust with Lakanto powdered sugar substitute before serving.
-
Frequently Asked Questions
Are lemons keto-friendly?
Yes, in the amounts a recipe like this uses. Lemon juice is low in carbohydrate, and the juice of two lemons spread across nine bars adds very little to each one; the Nutrition Facts panel has the per-bar numbers. The zest is where a lot of the flavor comes from, and a tablespoon of it adds almost nothing.
Do I really need to use fresh lemon juice for this recipe?
No, bottled lemon juice works. Read the label before you buy, though: some brands add sugar, which is the one thing you are trying to keep out of these.
Can I make my keto lemon bars more tart?
There is only the one batter here, so any adjustment goes in before it is spread — there is no separate filling to dose at the end.
Zest is the lever to use. It carries the lemon oils, which is where most of the aroma lives, and it adds no liquid at all — so it cannot affect how the bars set. The recipe uses a tablespoon, and going up from there is the safer of the two adjustments. Do it gradually rather than in one jump — the white pith under the peel is bitter, so there is a practical limit to how far down a lemon you can grate before the flavor turns.
Extra juice is the riskier route. This is an egg-set bake and the liquid is part of what the eggs have to hold, so adding more works against the set. If you go that way, keep it small.
Can I use almond meal as a substitute for almond flour?
Not as a like-for-like swap. This recipe is written for blanched almond flour, and gives no amounts for almond meal.
Almond meal is ground less finely and keeps the skins on, so it is a different ingredient rather than a coarser version of the same one. In a soft-set bar with nothing else in it to hide behind, both of those differences would be in every bite.
Can I refrigerate my keto lemon bars?
Yes, covered, and they freeze too. The storage section above has how long they keep, the paper-towel trick for the condensation, and how to freeze them without the bars fusing together.
Wrap Up
One bowl, one dish, about fifteen minutes to put together and twenty-five in the oven — plus the wait while they cool enough to cut cleanly. The Nutrition Facts panel has the numbers for a single bar.
If you make them, please rate the recipe below and tell us how they turned out in the comments. And if you post a photo on Instagram, tag it #buttertogetherkitchen so we can see it.
Correction — October 2, 2026: The powdered sweetener is for dusting the cooled bars; everything else goes into the bowl and is beaten together.
