01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - In a medium bowl, cream together the softened butter and powdered erythritol using an electric mixer or whisk until light and fluffy.
03 - Beat in the egg, vanilla extract, and maple extract until fully combined.
04 - In a separate bowl, whisk together the almond flour, coconut flour, and salt.
05 - Gradually add the dry ingredient mixture to the wet ingredients, mixing just until combined. Fold in the chopped walnuts.
06 - Scoop tablespoon-sized balls of dough onto the prepared baking sheet, spacing them about 2 inches apart. Flatten each cookie slightly with your fingers or the back of a spoon.
07 - Bake for 12 to 15 minutes, or until the edges are golden brown. Let cool completely on the baking sheet.
08 - In a small bowl, whisk together the walnut butter, powdered erythritol, maple extract, and heavy cream until smooth and drizzle consistency is reached.
09 - Drizzle the walnut butter mixture over the cooled cookies using a spoon or piping bag. Allow the drizzle to set before serving.