PREPARE cake batter and bake as directed on package for cupcakes. Pierce cooled cupcakes with a wooden skewer or large fork at 1/4-inch intervals.
DISSOLVE dry gelatin in boiling water. Carefully spoon 2 tsp. of the gelatin over each cupcake. Refrigerate 3 hours.
TINT whipped topping with food coloring; spread about 2 Tbsp. of the whipped topping onto each cupcake.
CUT each large marshmallow crosswise into 5 pieces with clean kitchen scissors to resemble flower petals. Arrange petals in a flower shape on top of each cupcake; place a miniature marshmallow in center of petals. Sprinkle each with 1/2 tsp. colored sugar.
To make cake instead of cupcakes, prepare batter as directed on package; pour into 13x9-inch baking pan. Bake as directed. Cool cake in pan on wire rack 15 min. Poke holes into cake and continue as directed.