Preheat oven to 350°F. Line two baking sheets with parchment paper or silicone baking mats. Set aside.
Combine the flour, baking soda, cinnamon, nutmeg, ginger, cloves and salt in a medium sized bowl, whisk and set aside.
Cream the butter and sugars together in a large mixer bowl until combined. It should be light in colour and fluffy.
Add the egg and vanilla extract and mix. Add the eggnog and mix until well combined.
Add the dry ingredients and mix until the flour is fully incorporated. Refrigerate for at least 1 hour.
Once cooled, scoop out cookie dough and roll into a ball. Place on cookie sheet.
Bake cookies for 9-11 minutes. The cookies will spread and the centers will look soft, but should look done. Remove just as the edges begin to turn golden.
Eggnog Glaze:
If using the glaze, combine the powdered sugar, eggnog and nutmeg in a small bowl and whisk to combine.
Drizzle the glaze over the cookies and allow to dry.