Preheat and prep: Heat your oven to 350°F (175°C). Line an 8-inch round cake pan or square pan with parchment and lightly grease the sides.

Mix dry ingredients: In a bowl, whisk 2 cups almond flour, 2 tablespoons coconut flour, 2 teaspoons baking powder, and 1/4 teaspoon sea salt until well combined.

Whisk the wet: In a separate bowl, whisk 3/4 cup granulated erythritol or allulose, 1/2 cup melted butter (cooled) or coconut oil, 3 large eggs, 1/2 cup unsweetened almond milk, 1 teaspoon vanilla, 1 tablespoon lemon zest, and 1 tablespoon lemon juice.

Combine: Pour the wet mixture into the dry and stir until just smooth. The batter will be thicker than traditional cake batter; that’s normal with almond flour.

Fold in blueberries: Gently fold in 3/4 cup blueberries. If using frozen, do not thaw; toss them with a teaspoon of almond flour first to reduce bleeding.

Fill the pan: Spread the batter evenly and smooth the top with a spatula. If you like, dot a few extra blueberries on top.

Bake: Bake 28–35 minutes, or until the top is golden and a toothpick comes out mostly clean with a few moist crumbs. Do not overbake.

Cool: Let the cake cool in the pan for 10 minutes, then lift it out using the parchment and transfer to a rack to cool completely.

Finish and serve: Dust with powdered sweetener and serve as-is or with lightly sweetened whipped cream. A few extra lemon zest curls are lovely.