Bake and cool bear cake using firm-textured batter such as pound cake. Trim off ears, muzzle and arms.
For arms, cut dowel rods to 4 in. long; insert at shoulder level. Using reserved cereal treats, form hands at ends of dowel rods and insert.
Lightly ice face area and mark facial features with toothpick. Outline and pipe in mouth, tongue and eyes with tip 3. Build up nose, fingers and toes with tip 5.
Cover face, body, arms, legs and overalls with tip 16 stars. Outline and pipe in 1 in. diameter buttons with tip 3 (smooth with finger dipped in cornstarch).
Overpipe rim and add dot buttonholes with tip 3. For party hat, cut sugar cone to 3 in. high and ice smooth.
Attach on head with dots of icing. Add tip 16 pull-out star pompom and brim. Pipe tip 3 number.