01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the almond flour, coconut flour, baking powder, and sea salt until evenly distributed.
03 - In a large bowl, beat the softened butter and sweetener with an electric mixer until light and fluffy, approximately 2 minutes.
04 - Add the egg and vanilla extract to the butter mixture, mixing until fully combined and smooth.
05 - Gradually stir the dry ingredient mixture into the wet mixture, mixing until a cohesive dough forms.
06 - Gently fold the chopped walnuts into the dough until evenly distributed throughout.
07 - Scoop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them about 2 inches apart. Flatten each portion slightly with your fingers or the back of a spoon.
08 - Bake for 13 to 15 minutes, or until the edges are golden brown and the centers appear set.
09 - Allow the cookies to cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely before serving.