1Heat oven to 350°F. Line 13x9-inch pan with foil so foil extends about 2 inches over sides of pan. Spray foil with cooking spray. Make and bake brownies as directed on box. Cool completely, about 1 hour.
2Remove brownies from pan by lifting foil; peel foil from sides of brownies. Continue as desired with options below. Flag Brownies: Frost brownies. Using red decorating gel, pipe stripes onto frosted brownie. Add decors in upper left corner of brownie. 24 brownies Firecracker Brownies: Using 1-inch round cookie cutter, cut out brownie rounds. Stack 2 brownie rounds together, spreading frosting between rounds and on top. Garnish with decors. 48 brownies Star Brownies: Using 2 1/2-inch star-shaped cookie cutter, cut brownies. Place frosting in resealable food-storage bag; cut off one bottom corner of bag. Pipe frosting on star-shaped brownies. Sprinkle with decors. 13 brownies