Prepare cake batter and bake in 2 (8-inch) round pans as directed on package. Cool cakes in pans 15 min. Invert onto wire racks; gently remove pans. Cool cakes completely.
Reserve 1/4 cup marshmallow creme for later use. Beat remaining marshmallow creme with cream cheese and vanilla in large bowl with mixer until blended. Gently stir in COOL WHIP.
Stack cake layers on plate, filling and frosting layers with cream cheese mixture.
Combine cereal and reserved marshmallow creme; shape into ball with moistened hands. Place on sheet of parchment.
Melt chocolate as directed on package; stir in food coloring. Pour just enough melted chocolate over cereal ball to completely coat ball. Reserve remaining melted chocolate for later use.
Dip open end of waffle cone in remaining melted chocolate; place on top of chocolate-coated cereal ball, pressing gently into ball to secure. Let stand 5 min. or until chocolate is firm.
Spread remaining melted chocolate onto top of cake, allowing some chocolate to drip down side of cake. Top cake with sprinkles and cone-topped cereal ball. Let stand 15 min. or until chocolate is firm.