1Butter bottom and sides of 13x9-inch pan. In very large bowl, place cereal. In 3-quart saucepan, heat butter and marshmallows over low heat, stirring constantly, until melted and smooth. Pour over cereal; stir until cereal is well coated.
2Using buttered back of spoon, press mixture evenly in pan. Let stand at room temperature about 1 hour or until firm.
3Loosen edges of cereal mixture with metal spatula; remove from pan. Cut into desired shapes with cookie cutters about 1 inch deep. In small bowl, microwave candy coating on High 1 to 2 minutes, stirring every 30 seconds, until melted and smooth. Dip tops of treats in coating, or drizzle coating over top of each. Sprinkle with edible glitter.