Preheat your oven to 325°F. If you prefer a slightly darker bottom on your cookies, you can set it to 350°F.
In a small bowl, whisk together the dry ingredients: all-purpose flour, baking powder, ground cinnamon, and ground nutmeg.
In a separate large bowl, use an electric mixer to cream together the granulated sugar and salted butter until light and fluffy.
Add the eggnog, vanilla extract, and egg yolks to the mixture and beat until combined.
Gradually mix in the dry ingredients until just combined.
Drop spoonfuls of dough onto an ungreased baking sheet, spacing them 1 inch apart.
Lightly sprinkle the tops with additional ground nutmeg.
Bake for about 15 minutes or until the bottoms turn light brown. Transfer to wire racks to cool.
