01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a bowl, whisk together almond flour, coconut flour, baking powder, and salt until well blended.
03 - In a large bowl, beat together the softened butter and granulated sugar until light and fluffy, about 2-3 minutes.
04 - Beat in the egg, vanilla extract, and almond extract until fully incorporated.
05 - Gradually add the dry ingredients to the wet ingredients, mixing on low speed until a soft dough forms.
06 - Gently fold in the mixed berries using a spatula, taking care not to crush them.
07 - Drop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them about 2 inches apart.
08 - If desired, sprinkle sliced almonds on top of each cookie dough mound.
09 - Bake for 10-12 minutes, or until the edges are lightly golden and the centers are set.
10 - Let cookies rest on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.