Preheat and prep: Heat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper, leaving overhang for easy lifting.

Make the crust: In a bowl, whisk almond flour, powdered sweetener, and salt. Stir in melted butter and vanilla until a dough forms that looks like damp sand and clumps when pressed.

Press and par-bake: Press the crust mixture firmly and evenly into the pan. Use the back of a measuring cup to flatten. Bake for 10–12 minutes, until edges are lightly golden.

Mix the filling: While the crust bakes, whisk eggs, powdered sweetener, lemon juice, lemon zest, almond flour, and salt until smooth. If using, whisk in heavy cream or coconut milk. The mixture should be pourable with no lumps.

Lower oven temperature: Reduce heat to 325°F (160°C) once the crust is done.

Pour and bake: Pour the lemon filling over the hot crust. Bake 16–20 minutes, or until the center is just set and barely jiggles when you tap the pan.

Cool completely: Let the bars cool in the pan on a rack, then chill for at least 2 hours to firm up. This step helps you get clean slices.

Slice and finish: Lift out using the parchment. Dust lightly with powdered sweetener if you like. Cut into 12 bars with a sharp knife, wiping the blade between cuts.