Preheat oven to 350 degrees Fahrenheit and line baking sheets with parchment or silicone baking mats
Add softened butter, shortening, and sugar to a mixing bowl and mix until light and fluffy.
Add the egg, vanilla, salt, nutmeg, and baking soda and mix until just combined.
Pour in 1/2 cup of your favorite eggnog and mix in.
Add 3 cups of flour and mix until incorporated.
Mix the sugar and ground nutmeg in a small bowl. Scoop 1 to 2 tbsp cookie dough balls and roll in sugar.
Place cookie dough balls on prepared baking sheet and press gently to flatten a bit.
Bake at 350 degrees fahrenheit for about 12 minutes, up to 14 if they are bigger cookies.