Preheat oven to 350°F. Line muffin tin with cupcake liners. Whisk together flour, sugar, nutmeg, baking powder and salt in a large mixing bowl. Set aside.
Next, in a large bowl with a hand or stand mixer fitted with a paddle attachment, beat together butter, egg whites, vanilla, eggnog and milk and on medium speed just until smooth.
Slowly, add the flour mixture and mix until just combined. Scoop the batter and full the cupcake liners ⅔ full.
Bake the cupcakes for 15-18 minutes until knife inserted in cupcakes comes out clean.
Allow the cupcakes to cool for one to two minutes, then transfer to pan to cool more.
Make the frosting with bourbon and eggnog. Frost the cupcakes.
Sprinkle with nutmeg and enjoy!