In a mixing bowl, add butter, eggs and eggnog; beat until smooth. Add cake mix, nutmeg and baking powder; mix until just combined into dough. Chill dough 1 hour so it is easier to handle.

Preheat oven to 350°F. Using a portion of the dough at a time to keep it chilled, make small balls of dough and roll them in granulated sugar. Place them on a cookie tray lined with parchment paper. Flatten them very slightly if you don’t want the cookies to bake up too round and tall.

Bake at 350° for about 10–12 minutes, until the edges are firm and golden brown.

While the cookies are baking, prepare glaze by combining eggnog and powdered sugar into a thick drizzling consistency. When the cookies have cooled down completely, drizzle them with eggnog glaze.