01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - In a medium bowl, whisk together almond flour, coconut flour, baking soda, and salt until well blended.
03 - In a large bowl, cream the softened butter with the brown sugar substitute until light and fluffy, approximately 2-3 minutes.
04 - Beat in the egg and vanilla extract until the mixture is smooth and fully combined.
05 - Gradually add the dry ingredients to the wet ingredients, mixing just until a soft dough forms. Be careful not to overmix.
06 - Scoop tablespoon-sized portions of dough, roll into balls, and place on the prepared baking sheet, spacing them 2 inches apart to allow for spreading.
07 - Gently flatten each ball slightly with your fingers or the back of a spoon to achieve desired cookie thickness.
08 - Bake for 10-12 minutes, or until the edges are lightly golden. The centers may still appear slightly soft.
09 - Allow cookies to cool on the baking sheet for 5 minutes to set, then transfer to a wire rack to cool completely.
10 - Once completely cooled, dust generously with powdered erythritol using a fine mesh sieve to create a snowy finish.