In a large mixing bowl, stir together the cake mix, egg whites, canola oil, and eggnog just until the mixture's smooth.
Gently fold in the chopped cranberries, cinnamon, and nutmeg.= until evenly incorporated.
Spoon the batter into 24 cupcake liners and bake at 350 degrees for 18-22, minutes or until a toothpick inserted in the center of a cupcake comes out clean.
For The Spiced White Chocolate Buttercream Frosting
Using a double boiler, melt the chocolate chips or wafers, stirring constantly until completely melted and smooth. Remove the chocolate from heat and let it rest/cool for a few minutes.
In the bowl of a stand mixer, whip together the softened butter and the softened cream cheese, until evenly combined and fluffy. Reduce speed and whisk the mixture while slowly pouring in the white chocolate. Whip the mixture or another minute to get it fluffy and evenly incorporated.
Add the powdered sugar, vanilla, spices, and eggnog. Beat for 2 minutes.
Refrigerate the frosting for 1-2 minutes to 'firm' up.
Frost the cupcakes as desired.
Sprinkle with a little additional spice, and top with a fresh cranberry, if desired.