In mixing bowl, mix cake mix, flour, cocoa powder and sugar. Blend in milk, eggs and butter.
Grease bundt pan with butter and pour in batter. Bake according to package instructions for bundt cakes then add 10-15 minutes. Let cool before icing.
To make frosting: In bowl, mix butter, cream cheese and whipping cream. Slowly blend in powdered sugar.
Ice entire bundt cake or place frosting in piping bag and pipe with back and forth “drip” motion. Sprinkle sanding sugar for sparkly snow appearance, if desired.