Preheat oven to 350°F. Fill 12-tin cupcake pan with holiday baking cups.
Blend together eggs and butter with an electric mixer until creamy. Add the Greek yogurt, eggnog, and cake mix. Blend on medium-high for 2 minutes. Pour batter into cupcake liners, filling about 3/4 full. Bake on 350°F for 26-28 minutes, or until cupcakes are golden brown.
While cupcakes bake, make the frosting. Mix together the butter and frosting mix with an electric mixer. Add in the eggnog until frosting is smooth. Fill a piping bag with frosting and a fitted tip, and refrigerate until cupcakes are cool.
Pipe frosting into a pretty design and top with crushed peppermint for an added pop of color if desired. Enjoy!