Lemon bars differ from dessert bars, like brownies or blondies, by being brighter in color and lighter in taste, injecting a sweet-tart dose of sunshine into any moment. This keto version is no different, offering all the flavors and textures you're accustomed to from a lemon bar: There's a shortbread crust that's not too crumbly, a gooey rich filling full of both lemon juice and freshly grated zest, and a light sprinkle of confectioners sweetener on top.
We've swapped out the sugar for powdered Swerve, a form of erythritol (a common non-caloric sugar alcohol used for low carb baking) that has prebiotics added to help stabilize it at high temperatures. We use almond flour instead of wheat in the crust, and also add almond flour to the filling in lieu of starch or pre-cooking the curd. The filling, due to not requiring stovetop cooking first like a standard lemon curd, actually makes this recipe easier to execute than a non-keto lemon bar! Quicker to make and free of sugar, grains, and gluten—what's not to love?
Gather the ingredients. Preheat the oven to 350 F.
Make the crust by mixing together almond flour, butter, sweetener, and egg yolk with a fork until a crumbly dough is formed.
Press the dough into a greased or parchment-lined 9x9 or 11x7-inch baking dish, and bake for 15 minutes, until lightly golden.
While the crust bakes, make the filling. Mix the lemon juice, lemon zest, powdered Swerve, almond flour, and egg yolks in a bowl together with a whisk.
Remove crust from oven and immediately pour filling in; return to oven.
Bake for an additional 10 minutes until filling is cooked through and only slightly jiggly. Let cool completely. Once cooled, refrigerate for at least 2 hours before slicing.
Slice into 12 bars, and dust with confectioners' sweetener. Enjoy!
- Any powdered cup-for-cup style non-caloric sweetener would work—provided it's powdered and not granular. Other examples to use are powdered monk fruit or a powdered monk fruit/erythritol blend.
- It's imperative to refrigerate the bars before slicing in order for them to be as firm as possible.
- Fresh lemon juice is inimitable; you won't get the same brightness from bottled.
- If you don't have a microplane to create lemon zest, it can be substituted out for 1/4 teaspoon lemon extract.
- For a firmer/more crumbly crust, omit the egg yolk.
- Don't poke holes in the crust as the filling will leak through if you do; if crust bubbles after blind bake, press lightly on bubbles with a fork before adding the filling.
- Once baked, discolorations of white and yellow on top of the bars, as well as cracking after cooling, are normal and not a problem. Both will be hidden by the confectioners' sweetener added before serving.
- Lemon bars should be kept in the refrigerator and eaten within 2 to 3 days, or freeze them for up to 2 to 3 months—just make sure they're double wrapped.