Preheat your oven to 300 degrees.
Cream together your sugar and butter in a large bowl.
Add in your eggnog, vanilla and egg yolks.
Mix until smooth.
Combine your flour, baking powder, cinnamon, nutmeg and salt in a separate bowl.
Mix your dry flour mixture into the wet mixture.
Stir together until just combined.
Drop in rounded 1 TBS balls onto a cookie sheet lined with parchment paper.
Sprinkle tops lightly with nutmeg.
Bake for 13-15 minutes until cookies just barely look done.
Leave cookies on cookie sheet for 2 minutes before removing them to a cooling rack to cool completely.