Preheat oven to 350. In large bowl, combine first 4 ingredients according to cake mix package directions. Fill each cone with about 2 1/2 tbsp of batter. Place cones about 3" apart on an ungreased baking sheet. Bake 25 to 30 minutes. Cool completely. For icing, beat all ingredients together in large bowl until smooth. Ice each cupcake with about 1 tbsp icing. Before icing hardens decorate with candy and/or sprinkles. Store in airtight container.