Keto Lemon Bars
A buttery almond shortbread base under a bright, tangy lemon curd layer that sets smooth and glossy. Sharp, sunny and a worthy stand-in for the bake-sale classic.
Nutrition per serving
1 bar (2-inch square)- Net carbs
- 1.5g
- Calories
- 100kcal
- Protein
- 3.6g
- Fat
- 8.7g
- Total carbs
- 12 g
- Fiber
- 1.1 g
Calculated from USDA FoodData Central values for each ingredient (optional ingredients excluded). Brands vary — check your labels if you track closely.
Ingredients
Lime bars: Fresh lime juice and zest in place of lemon for a sharper, more floral bar in the spirit of key lime pie.
- Use the lime juice and zest exactly as you would the lemon. Key limes work too; you will need about 15 of them for ½ cup of juice.
Nut-free (coconut flour crust): A coconut flour shortbread base, held together with an egg and a little extra butter, makes the bars nut-free.
- For the crust, stir the coconut flour, 2 tablespoons powdered erythritol and salt with all 6 tablespoons of melted butter and the egg into a soft dough. Press it evenly into the pan with damp fingers.
- Bake 12–15 minutes until golden at the edges, then pour the filling over the warm crust and continue as written.
- Shortbread crust
- Lemon filling
- Nice to have (optional)
- Shortbread crust
- Lemon filling
- Nice to have (optional)
- Shortbread crust
- Lemon filling
- Also add
- Nice to have (optional)
Estimated cost $8.12 for 16 servings ($0.51 each) · how we estimate
Instructions
-
Heat the oven to 350°F (175°C). Line an 8-inch square pan with parchment, leaving an overhang on two sides.
-
Stir the almond flour, 2 tablespoons powdered erythritol, salt and melted butter into a damp, crumbly dough. Press it firmly and evenly into the pan and prick it a few times with a fork.
-
Bake the crust 12–15 minutes, until the edges are light golden. Lower the oven to 325°F (165°C).
-
While the crust bakes, whisk the eggs and 1 cup powdered erythritol until smooth (mix, do not whip to a foam). Whisk in the lemon juice, zest and coconut flour, let stand 5 minutes so the coconut flour hydrates, then whisk again.
-
Skim off any foam, pour the filling over the warm crust and bake 18–22 minutes, until the filling is set at the edges and the center only trembles slightly — no liquid should slosh when you nudge the pan.
-
Cool to room temperature, then refrigerate at least 2 hours, until firm. Lift out by the parchment, dust with powdered erythritol if you like, and cut into 16 squares with a sharp knife wiped clean between cuts.
Tips for success
-
Pour the filling onto the crust while it is still warm; this seals the surface and keeps the base crisp instead of soggy. - Powdered erythritol is a must for a smooth, curd-like filling, and its slight cooling note suits lemon. Avoid allulose here — it browns faster and would color the pale top.
- Fresh lemons make all the difference. Bottled juice tastes flat and slightly bitter once baked.
Nice to have, not needed
- A microplane makes quick work of the zest — the fine side of a box grater works too.
Storage & meal prepMeal-prep friendly
- Keeps 5 days in the fridge
- Freezes up to 2 months
Reheat: Serve chilled.
Prep tip: Freeze the cut bars in a single layer, then dust with sweetener after thawing.
Refrigerate in an airtight container up to 5 days, or freeze up to 2 months. Dust with sweetener just before serving, as it slowly dissolves into the filling.
Variations
2 variations, each with its own ingredients and macrosLime bars
FlavorFresh lime juice and zest in place of lemon for a sharper, more floral bar in the spirit of key lime pie.
- fresh lemon juice → fresh lime juice
- lemon zest → lime zest
1.6 g net · 100 kcal · 3.6 g protein · 8.7 g fat · ≈$0.51 per serving (+0.1 g net carbs vs the original)
Nut-free (coconut flour crust)
DietA coconut flour shortbread base, held together with an egg and a little extra butter, makes the bars nut-free.
- blanched almond flour → coconut flour
- + 2 tbsp extra butter
- + 1 large egg
1.5 g net · 80 kcal · 2.8 g protein · 6.3 g fat · ≈$0.40 per serving (same net carbs as the original)
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