Prepare the Dough:

• In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy (2–3 minutes).
• Beat in the eggs one at a time, then add the vanilla extract.
• In a separate bowl, whisk together the flour, baking powder, and salt.
• Gradually add the dry ingredients to the wet mixture, mixing until a soft dough forms. Chill the dough for 30 minutes.

Prepare the Filling:

• In a medium bowl, combine ground walnuts, sugar, cinnamon, nutmeg, melted butter, and milk. Mix until evenly combined.

Roll and Fill:

• Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper.
• On a floured surface, roll out the dough to ¼-inch thickness.
• Spread an even layer of the walnut filling over the dough, leaving a ½-inch border around the edges.
• Roll the dough tightly into a log and slice into 1-inch pieces.

Bake:

• Place the slices onto the prepared baking sheets, spacing them 2 inches apart.
• Bake for 12–15 minutes or until the edges are golden brown.
• Cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

Garnish and Serve:

• Dust the cooled cookies generously with powdered sugar before serving.