Preheat and prep: Heat your oven to 350°F (175°C). Line a baking sheet with parchment paper to prevent sticking and promote even browning.

Soften the butter: Let 6 tablespoons of unsalted butter sit at room temperature until soft. You should be able to press it easily with a fingertip without it melting.

Cream the butter and sweetener: In a bowl, beat the softened butter with 1/2 cup granulated keto sweetener until light and creamy, about 1–2 minutes. This step helps with texture and even sweetness.

Add egg and flavor: Mix in 1 large egg, 1 teaspoon vanilla extract, and 1/2 teaspoon almond extract if using. Stir in 1 teaspoon finely grated lemon zest for brightness.

Combine dry ingredients: In a separate bowl, whisk together 2 cups fine almond flour, 1 teaspoon baking powder, 1/4 teaspoon salt, and 1/4 teaspoon xanthan gum if using. Xanthan gum adds a little chew, but it’s optional.

Bring the dough together: Add the dry ingredients to the wet mixture and stir until a soft dough forms. It should be thick and scoopable, not runny.

Fold in blueberries: Gently fold in 3/4 cup blueberries. If using frozen, do not thaw; toss them lightly in almond flour first to reduce bleeding. Be gentle to keep them from breaking.

Portion the cookies: Scoop the dough into 12 mounds (about 1.5 tablespoons each). Place them on the prepared sheet, spacing them about 2 inches apart. Flatten slightly with your fingers; almond flour cookies don’t spread as much as wheat-based ones.

Bake: Bake for 11–14 minutes, until the edges are set and lightly golden. The centers may look a touch soft, which is perfect for a tender cookie.

Cool completely: Let the cookies cool on the baking sheet for 10 minutes, then transfer to a rack. They firm up as they cool, so don’t move them too soon.

Optional finishing touch: For extra flavor, dust the tops with a small sprinkle of granulated sweetener mixed with a pinch of lemon zest after baking.