PREPARE cake batter and bake as directed on package for 24 cupcakes; cool in pan 10 min.
ADD boiling water to gelatin mix; stir 2 min. until completely dissolved. Cut small "X" in top of each cupcake with sharp knife. Carefully spoon gelatin over cupcakes, adding about 2 tsp. to each. Refrigerate 30 min.
MEANWHILE, melt chocolate as directed on package; pour into resealable plastic bag. Snip small piece off one bottom of bag; use to pipe chocolate into spider web shapes on parchment- or waxed paper-covered baking sheet. Refrigerate 30 min. or until firm.
WHISK marshmallow creme and COOL WHIP until blended. Stir in food coloring; spread onto cupcakes. Top with chocolate spider webs.