Prep your pan and oven. Preheat oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment, leaving overhang for easy removal. Lightly grease the parchment.

Mix dry ingredients. In a medium bowl, whisk together 2 cups almond flour, 2 tablespoons coconut flour, 2/3 cup granulated keto sweetener, 1 teaspoon baking powder, and 1/4 teaspoon salt. Break up any almond flour clumps.

Combine wet ingredients. In a large bowl, whisk 1/2 cup melted butter (slightly cooled), 2 large eggs, 2 teaspoons vanilla extract, 1 tablespoon lemon zest, and 3 tablespoons fresh lemon juice until smooth.

Bring it together. Add the dry mixture to the wet and stir until just combined. The batter will be thick and scoopable, not runny. If it seems too dry, add 1–2 teaspoons more lemon juice or a splash of almond milk.

Spread and smooth. Transfer the batter to the prepared pan. Use an offset spatula to press it evenly into the corners and smooth the top.

Bake. Bake for 18–22 minutes until the edges are lightly golden and the center is just set. A toothpick should come out with a few moist crumbs, not wet batter.

Cool completely. Let the blondies cool in the pan on a rack. This helps them firm up for clean slicing.

Make the glaze. In a small bowl, whisk 3/4 cup powdered keto sweetener with 1–2 tablespoons lemon juice and 1 tablespoon heavy cream or almond milk to a pourable consistency. Add a pinch of lemon zest for extra zing.

Glaze and set. Pour the glaze over the cooled blondies and spread evenly. Let it set for 20–30 minutes before slicing.

Slice and serve. Lift out using the parchment and cut into 16 squares. Enjoy chilled or at room temperature.