1. In a medium bowl, whisk together flour, baking powder, salt, and nutmeg.

2. In a large bowl, beat softened butter and sugar until light and fluffy.

3. Add egg yolk, vanilla extract, and eggnog. Mix until well combined.

4. Gradually add the dry ingredients to the wet, mixing until dough forms.

5. Divide dough into 2 discs, wrap, and chill for 1 hour.

6. Preheat oven to 350°F (175°C) and line baking sheets with parchment.

7. Roll dough to ¼ inch thick, cut with cookie cutters, and place on sheets.

8. Bake for 8–10 minutes until edges are lightly golden.

9. Cool on baking sheet for 5 minutes, then transfer to wire rack.

10. In a bowl, whisk powdered sugar and eggnog to make glaze.

11. Spread glaze on cooled cookies and sprinkle with nutmeg or sprinkles.

12. Let glaze set at room temperature for 30–60 minutes before serving.