Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until the mixture is light and fluffy.
Add the eggs, eggnog, and vanilla extract to the mixture, and beat until well combined.
In another bowl, whisk together the all-purpose flour, baking powder, ground nutmeg, and salt.
Gradually add the dry ingredients to the butter mixture, mixing until just combined. Be careful not to overmix.
Using a spoon or cookie scoop, drop rounded tablespoons of dough onto the prepared baking sheet, leaving space between each cookie.
Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden. The center may look slightly soft but will firm up as they cool.
Remove the cookies from the oven and let them cool on the baking sheet for a few minutes before transferring them to a cooling rack.
Once completely cooled, dust the cookies with powdered sugar.