Lemon Bars with an Almond Crust
A buttery almond flour shortbread crust under a bright, silky lemon filling of eggs, fresh juice, and zest, sweetened with allulose and chilled until firm.
Why you'll love Lemon Bars with an Almond Crust
Lemon bars are a spring bake-sale and Easter-table classic: a crisp, buttery shortbread base and a tart lemon layer that sets into a soft, sliceable custard. This version keeps both layers and sweetens them with allulose, so the lemon tastes bright and sharp and the crust tastes of toasted almonds and butter.
The crust is almond flour pressed firmly into the pan and baked until golden before the filling goes on, which seals it and keeps it crisp under the wet layer. The filling sets from eggs alone: as it bakes, the egg proteins firm up around the lemon juice into a smooth custard. Allulose browns faster than sugar, so the oven runs at a moderate 325°F (165°C), which lets the crust turn golden and the filling set without the edges darkening. A long chill finishes the job, firming the filling so the bars cut into neat squares.
Make them a day ahead for a spring gathering. They taste best cold, with a light dusting of powdered allulose right before serving.
Quick overview: This Lemon Bars with an Almond Crust takes 15 min of hands-on time and about 3 hr 55 min in all and makes 16 servings, each 1 bar (2-inch square). You'll need a baking dish.
Ingredients
- 1 1/2 cups plus 2 tbsp almond flour, divided
- 1 cup granulated allulose, divided, plus 1 tbsp powdered allulose for dusting Label: allulose, and nothing else
- 1/4 tsp fine sea salt, divided
- 5 tbsp butter, melted
- 4 large eggs, at room temperature
- 1/2 cup fresh lemon juice (from about 3 lemons)
- 1 tbsp finely grated lemon zest
Instructions
- Heat the oven and line the pan: Heat the oven to 325°F (165°C). Line an 8-inch square baking dish with parchment, leaving an overhang on two sides so you can lift the bars out in one piece.
- Make the crust: Stir together 1 1/2 cups of the almond flour, 1/4 cup of the allulose, and half the salt, then pour in the melted butter and stir until it looks like damp sand and holds together when squeezed. Press it into an even layer over the bottom of the baking dish, using the bottom of a measuring cup to pack it firmly. A tightly packed crust bakes up crisp and holds its shape when cut.
- Bake the crust: Bake for 15 to 18 minutes, until the edges are golden and the center looks dry and lightly colored. Baking the crust first sets it so the filling sits on top in place of soaking in.
- Mix the filling: While the crust bakes, whisk the eggs with the remaining 3/4 cup of allulose until smooth, then whisk in the remaining 2 tablespoons of almond flour, the lemon juice, the lemon zest, and the rest of the salt. Whisk gently; beating hard works in bubbles that rise and leave a foamy top.
- Bake the bars: Pour the filling over the hot crust, and bake for 20 to 25 minutes, until the edges are set and the center wobbles only slightly when you nudge the dish. Pouring onto a hot crust helps the bottom of the filling set right away and bond to it.
- Cool and chill: Cool the bars in the dish on a rack for 1 hour, then refrigerate for at least 2 hours, until cold and firm. The filling finishes setting as it chills.
- Cut and serve: Lift the bars out by the parchment and cut them into 16 squares with a sharp knife, wiping the blade with a damp towel between cuts. Dust with powdered allulose just before serving.
Storage and leftovers
Keep the bars in a sealed container in the refrigerator for up to 4 days. Allulose keeps the filling softer than sugar does, so they are best served straight from the refrigerator.
To freeze, wrap the cut, undusted bars well and freeze them for up to 2 months. Thaw them overnight in the refrigerator and dust them just before serving.
Variations
- Meyer lemon: Use Meyer lemon juice and zest for a sweeter, more floral bar, and cut the allulose in the filling to 2/3 cup.
- Lime: Use fresh lime juice and zest for a sharper, key lime style bar.
- Orange and lemon: Use 1/4 cup fresh orange juice and 1/4 cup lemon juice, with orange zest in place of the lemon zest, for a softer, rounder citrus flavor.
- With berries: Serve each bar with a few fresh raspberries or blueberries.
Notes and tips
- Zest before you juice: Grate the zest from whole lemons first, then halve and juice them. Zesting a squeezed lemon is nearly impossible.
- Use fresh juice: Bottled lemon juice tastes flat and sometimes bitter. Three or four fresh lemons give the bright flavor these bars depend on.
- Measure allulose by weight: Allulose is a little less sweet than sugar, and measuring by weight gives the same result every time.
- Dust at the last minute: Powdered allulose dissolves into the moist surface over time, so dust the bars right before they go to the table.
Nutrition and mindful eating
- Almond flour brings fiber, vitamin E, and real fat to the crust, and butter gives it its crisp, shortbread texture.
- Eggs set the filling and add protein, which gives each small bar real staying power.
- Allulose sweetens the bars with no effect on blood sugar, and the tart lemon means a little sweetness reads as plenty.
- Fresh lemon juice and zest carry most of the flavor, bright enough that one square feels like a complete dessert.
- As you eat, notice how the tart lemon and the buttery almond crust feel together, and check in afterward on whether one bar leaves you satisfied, with no pull toward a second.
Frequently asked questions
Have a question about this Lemon Bars with an Almond Crust? Start here, with the questions people ask most.
Why is my filling foamy on top?
Too much whisking works air into the eggs. Whisk just until smooth, and let the filling sit for a minute so bubbles rise and pop before you pour.
Can I use monk fruit or stevia?
Allulose behaves most like sugar in a baked custard. Monk fruit and stevia blends vary widely in sweetness and some contain fillers, so read the label and expect a different texture.
Why bake at 325°F?
Allulose browns faster than sugar. A moderate oven lets the crust turn golden and the filling set without dark edges.
How do I get neat squares?
Chill the bars completely, then cut with a sharp knife, wiping the blade with a damp towel between each cut.
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