Preheat oven to 350 degrees F. Line a cupcake pan with paper liners.

In a large bowl, combine butter,sugar egg whites, eggnog, milk, vanilla, and nutmeg.

Stir in baking powder and flour a little at a time until just combined. Do not over mix.

Fill cupcakes liners ~¾ of the way full.

Bake for 18-20 minutes or until a toothpick inserted in the center of the cupcake comes out clean.

Cool in pan for 3-4 minutes. Remove to wire racks to cool completely before frosting.

In a large bowl, combine butter and shortening.

Stir in eggnog, rum extract, and nutmeg.

Gradually add powdered sugar a little at a time until you reach your desired consistency. Add more eggnog if icing is too thick.

Spread or pipe frosting onto your eggnog cupcakes.