Keto Lemon Bars Recipe
Bright, tangy, and perfectly sweet, this Keto Lemon Bars Recipe gives you all the classic lemon bar flavor with a fraction of the carbs and zero sugar crash.
If you’ve been missing that bakery-style lemon square on your ketogenic or low carb way of eating, you’re in the right place. These keto lemon bars are made with an almond flour shortbread crust, a silky lemon custard topping, and no refined sugar—just a clean, low sugar lemon dessert that tastes like sunshine on a plate. I love serving these at spring gatherings, summer cookouts, or honestly any Sunday afternoon when I want something sweet but still feel good about my choices.
Why You’ll Love This Keto Lemon Bars Recipe
- True lemon bar flavor, without the sugar – You still get that tart-sweet punch, but these are sugar free lemon bars made with low-carb sweeteners.
- Perfect for keto, low carb, and gluten free eaters – The almond and coconut flour crust makes them naturally gluten free and grain free lemon bars.
- Simple pantry ingredients – No fancy products; just real butter, fresh lemon, eggs, and low carb flours you probably already use in keto baking recipes.
- Great make-ahead dessert – They actually taste better after chilling, so you can bake them a day ahead for parties or holidays.
- Easy to slice, pack, and share – These keto dessert bars hold up well on a cookie tray, in lunch boxes, or for potlucks.
- Customizable sweetness and tartness – You can tweak the sweetener or lemon juice to get the exact balance your family likes.
- Lower carb than traditional lemon bars – Each bar has just about 3–4 grams of net carbs, depending on your sweetener and how you slice them.
- Beginner-friendly – Even if you’re new to low carb dessert recipes, this one is very forgiving and great for building your keto baking confidence.
Ingredients
Here’s everything you need to make these easy keto lemon bars. I’ll list the main ingredients first, then mention a few simple swaps.
Crust for Keto Lemon Bars
- 1 ½ cups blanched almond flour
- This creates a tender, buttery shortbread base for almond flour lemon bars. Use superfine almond flour (not almond meal) for the best texture.
- ¼ cup coconut flour
- Helps the crust hold together without gluten and keeps these grain free lemon bars from getting soggy.
- ⅓ cup powdered erythritol, allulose, or monk fruit blend
- Powdered sweetener dissolves more smoothly than granular here. Use your favorite keto-friendly brand.
- ½ teaspoon fine sea salt
- Balances the sweetness and brightens the lemon flavor later.
- ½ cup unsalted butter, melted and slightly cooled
- Real butter gives that classic shortbread taste and rich mouthfeel.
- 1 teaspoon vanilla extract
- Adds warmth and bakery-style flavor to the crust.
Lemon Filling
- 4 large eggs, at room temperature
- They’re the backbone of the custard. Room temp eggs mix more smoothly and help prevent curdling.
- ¾ cup powdered erythritol, allulose, or monk fruit blend
- Makes the filling sweet but keeps this a low sugar lemon dessert. Taste your batter before baking and adjust by 1–2 tablespoons if you prefer sweeter bars.
- ½ cup fresh lemon juice (about 3–4 medium lemons)
- Fresh juice really matters for healthy lemon bars—bottled juice tends to taste dull.
- 1 tablespoon finely grated lemon zest
- Use organic lemons if you can, and zest only the bright yellow part, not the white pith.
- ½ cup heavy whipping cream
- Adds creaminess and gives these keto friendly dessert bars a silky, custard-like texture.
- 2 tablespoons coconut flour
- Thickens the filling without cornstarch or regular flour, keeping this a low carb lemon bars recipe.
- ½ teaspoon vanilla extract
- Adds a little roundness to balance the tart lemon.
- Pinch of salt
- Just a pinch makes the lemon pop.
Optional Topping
- 2–3 tablespoons powdered keto sweetener, for dusting
- Extra lemon zest, for garnish
Substitution notes:
- For nut-free, you can experiment with all coconut flour in the crust, but it’s a very absorbent flour. Start with ½ cup coconut flour plus a little extra butter and test the texture.
- For dairy-free, you can use coconut oil in the crust and full-fat coconut milk in the filling. The flavor will lean slightly tropical but still delicious.
Directions
You’ll need an 8×8-inch (20 cm) baking pan, parchment paper, and a whisk.
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Preheat and prep the pan
Preheat your oven to 350°F (175°C). Line your baking pan with parchment paper, letting it hang over the sides like handles. This makes the keto lemon bars easier to lift out and slice later. -
Mix the crust ingredients
In a medium bowl, whisk together the almond flour, coconut flour, powdered sweetener, and salt. Pour in the melted butter and vanilla, then stir with a fork or spatula until the mixture looks like soft, slightly crumbly dough that holds together when pressed. -
Press and bake the crust
Transfer the crust mixture to your prepared pan. Use your fingers or the back of a measuring cup to press it into an even layer, paying attention to the corners. Bake for 10–12 minutes, until the edges are just turning golden. You don’t want it too dark, because it will bake again with the filling. -
Let the crust cool slightly
Pull the pan from the oven and set it on a cooling rack. Let the crust cool for about 5–10 minutes while you mix the lemon filling. If you pour the filling onto a super hot crust, the eggs may cook unevenly. -
Whisk the wet filling ingredients
In a large bowl, whisk the eggs, powdered sweetener, lemon juice, lemon zest, heavy cream, vanilla, and salt. Whisk until smooth and slightly frothy. This is a good time to taste a small spoonful; if you like a sweeter lemon bar, sprinkle in another tablespoon or two of sweetener and whisk again. -
Add the coconut flour
Sprinkle the coconut flour over the mixture and whisk well to break up any small lumps. Let it sit for 2–3 minutes, then whisk again. Coconut flour thickens as it sits; you want a pourable but slightly thickened batter. -
Bake the lemon bars
Carefully pour the lemon filling over the warm crust, tilting the pan gently to spread it out evenly. Bake at 350°F for 18–22 minutes, or until the edges are set and the center still has a tiny jiggle when you nudge the pan. The top may look slightly puffy—that’s normal. -
Cool completely, then chill
Set the pan back on the cooling rack and let the bars come to room temperature. Then cover the pan and chill in the refrigerator for at least 3 hours, or overnight. This step is key for clean slices and the right custard texture. -
Slice and serve
Once fully chilled, use the parchment “handles” to lift the whole slab out of the pan. Place on a cutting board, dust with powdered keto sweetener if you like, and cut into 16 small or 9 larger squares. Wipe your knife between cuts for the neatest edges.
Servings & Timing
- Yield: 16 small bars (or 9 larger bars)
- Prep Time: 15–20 minutes
- Bake Time: 28–34 minutes total
- Chill Time: 3 hours (or overnight)
- Total Time: About 4 hours, mostly hands-off
For everyday snacking, I usually slice these into 16 pieces. For parties, I’ll sometimes cut each square in half again so guests can try a few different keto dessert bars from the dessert table.
Variations
You know what? Once you have this base recipe down, you can play with it a bit. Here are some fun ideas:
- Meyer Lemon Bars – Use Meyer lemons for a naturally sweeter, more floral ketogenic lemon dessert.
- Coconut Flour Lemon Bars – Increase coconut flour in the crust (and decrease almond flour) for a more coconut-forward, nutty twist—great for coconut flour lemon bars fans.
- Berry Swirl Lemon Bars – Swirl ¼ cup mashed raspberries or blueberries into the filling before baking for a pretty marbled look.
- Extra Tangy Lemon Bars – Add an extra 2 tablespoons of lemon juice and 1 teaspoon of zest for those who like a sharper, tangier low carb lemon bars recipe.
- Lemon Cheesecake Bars – Whisk 4 ounces softened cream cheese into the filling for an ultra-creamy texture that tastes like a lemon cheesecake square.
- Lemon-Lime Bars – Replace half the lemon juice with fresh lime juice for a fun citrus blend that works so well in summer.
Storage & Reheating
These keto friendly dessert bars are actually better the next day, which makes them a gift to your future self.
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Refrigerator:
Store the lemon bars in an airtight container in the fridge for up to 5 days. Place parchment or wax paper between layers if you stack them, so they don’t stick. -
Freezer:
For longer storage, arrange sliced bars on a baking sheet, freeze until solid, then move them to a freezer-safe container or bag. They’ll keep well for 2–3 months. -
Thawing:
Thaw frozen bars in the fridge overnight, or at room temperature for about 30–40 minutes. I like them chilled but not rock cold, so the lemon flavor really shines.
These don’t really need reheating, since they’re meant to be enjoyed chilled or at cool room temperature—similar to cheesecake bars.
Notes from My Kitchen
- Taste as you go: Low-carb sweeteners can vary in sweetness (and aftertaste), so always taste your filling before baking. That’s one of the joys of sugar free lemon bars—you can adjust without worrying about over-caramelizing sugar.
- Fresh lemons make a big difference: Bottled lemon juice works in a pinch, but fresh juice and zest give a much brighter flavor, especially in a simple keto baking recipe like this.
- Don’t skip the chill: If you cut the bars while warm, the filling will seem too soft and you might think you did something wrong. Chill them fully, then judge the texture. Most of the “my keto lemon bars didn’t set” messages I get are from impatient slicers—no shame, I’ve been there.
- On sweeteners: Allulose tends to give the smoothest texture and doesn’t crystallize in the fridge. Erythritol-based sweeteners can occasionally feel a little cool or grainy if not fully dissolved. Powdered form helps a lot.
- Pan size matters: An 8×8 pan gives thicker, classic lemon bars. A 9×9 pan will make thinner bars and may bake a bit faster—start checking a couple of minutes early.
FAQs
Are these keto lemon bars really low carb?
Yes. When made as written and cut into 16 pieces, each bar is typically around 3–4 grams of net carbs, depending on your brand of sweetener and exact flours.
Can I use granular sweetener instead of powdered?
You can, but powdered sweetener dissolves better, especially in the filling, and gives a smoother texture for your low carb dessert recipe.
My lemon bars cracked on top—what happened?
A few small cracks are normal. Big cracks usually mean the bars were baked a little too long or the oven was too hot; they’ll still taste great, and a dusting of powdered sweetener hides a lot.
The filling seems too soft—how can I fix it next time?
First, be sure they’re fully chilled. If they’re still too soft, add an extra ½ tablespoon of coconut flour next time, or bake for 2–3 more minutes until the center only slightly jiggles.
Can I make these dairy-free?
Yes. Use coconut oil instead of butter in the crust and full-fat canned coconut milk in place of the heavy cream. The flavor will be a bit different but still works well for healthy lemon bars.
Can I make these without coconut flour?
You can replace the coconut flour in the filling with ½ teaspoon xanthan gum, whisked in very well, but the texture will be a little different. For the crust, replace the ¼ cup coconut flour with about ¾ cup extra almond flour, then watch the bake time.
Do these taste like “real” lemon bars?
They really do. The texture is a touch more custardy than some classic recipes, but the bright, buttery, lemony taste is exactly what most people remember—just without the sugar spike.
Can I double the recipe for a crowd?
Yes, double everything and bake in a 9×13-inch pan. The crust and filling thickness should be similar; add a few minutes to the bake time for the filling and keep an eye on that gentle center jiggle.
Conclusion
This Keto Lemon Bars Recipe brings the bright, nostalgic flavor of classic lemon bars together with smart, low carb ingredients—so you can enjoy dessert and still feel steady and satisfied. Whether you’re serving a crowd, treating your family, or cutting a few bars to tuck into your lunch box, these low carb lemon bars are a dependable, happy little treat.
If you try this recipe, let me know how it goes—tell me if you made any twists or used it alongside other keto dessert bars for a party tray. And if you loved these, you might enjoy exploring more gluten free lemon bars or other keto baking recipes like brownies, cheesecake bars, and cookies next.
Keto Lemon Bars
Ingredients
- 1 1/2 cups blanched almond flour superfine; for crust
- 1/4 cup coconut flour for crust
- 1/3 cup powdered erythritol, allulose, or monk fruit blend for crust
- 1/2 teaspoon fine sea salt for crust
- 1/2 cup unsalted butter melted and slightly cooled; for crust
- 1 teaspoon vanilla extract for crust
- 4 large eggs at room temperature; for filling
- 3/4 cup powdered erythritol, allulose, or monk fruit blend for filling; adjust to taste
- 1/2 cup fresh lemon juice about 3–4 medium lemons
- 1 tablespoon finely grated lemon zest
- 1/2 cup heavy whipping cream
- 2 tablespoons coconut flour for filling
- 1/2 teaspoon vanilla extract for filling
- 1 pinch salt for filling
- 2 tablespoons powdered keto sweetener for dusting; optional
- extra lemon zest for garnish; optional
Instructions
- Preheat the oven to 350°F (175°C). Line an 8x8-inch (20 cm) baking pan with parchment paper, letting it hang over the sides to create handles for easy removal later.
- In a medium bowl, whisk together the almond flour, 1/4 cup coconut flour, 1/3 cup powdered keto sweetener, and 1/2 teaspoon fine sea salt. Pour in the melted butter and 1 teaspoon vanilla extract and stir until the mixture forms a soft, slightly crumbly dough that holds together when pressed.1 1/2 cups blanched almond flour, 1/4 cup coconut flour, 1/3 cup powdered erythritol, allulose, or monk fruit blend, 1/2 teaspoon fine sea salt, 1/2 cup unsalted butter, 1 teaspoon vanilla extract
- Transfer the crust mixture to the prepared pan. Press into an even layer, making sure to reach the corners. Bake for 10–12 minutes, until the edges are just turning golden. Do not overbake, as the crust will bake again with the filling.
- Remove the pan from the oven and place it on a cooling rack. Let the crust cool for 5–10 minutes while you prepare the lemon filling.
- In a large bowl, whisk together the eggs, 3/4 cup powdered keto sweetener, lemon juice, lemon zest, heavy whipping cream, 1/2 teaspoon vanilla extract, and a pinch of salt. Whisk until smooth and slightly frothy. Taste and add 1–2 tablespoons more sweetener if you prefer a sweeter filling.4 large eggs, 3/4 cup powdered erythritol, allulose, or monk fruit blend, 1/2 cup fresh lemon juice, 1 tablespoon finely grated lemon zest, 1/2 cup heavy whipping cream, 1/2 teaspoon vanilla extract, 1 pinch salt
- Sprinkle the 2 tablespoons coconut flour over the filling mixture and whisk well to break up any lumps. Let the mixture sit for 2–3 minutes to allow the coconut flour to thicken, then whisk again. The batter should be pourable but slightly thickened.2 tablespoons coconut flour
- Carefully pour the lemon filling over the warm crust, tilting the pan gently to spread it evenly. Bake at 350°F (175°C) for 18–22 minutes, or until the edges are set and the center still has a tiny jiggle when the pan is nudged. The top may puff slightly; this is normal.
- Place the pan on a cooling rack and let the bars cool to room temperature. Cover the pan and chill in the refrigerator for at least 3 hours, or overnight, until fully set.
- Use the parchment paper handles to lift the chilled slab out of the pan and place it on a cutting board. Dust with powdered keto sweetener and garnish with extra lemon zest if desired. Cut into 16 small or 9 larger squares, wiping the knife between cuts for neat edges.2 tablespoons powdered keto sweetener, extra lemon zest
