Over med. heat, melt butter and add marshmallows, stirring until smooth.Pour cereal, candy corn and chocolate chips into lg. bowl. Pour butter and marshmallows over cereal mixture, stirring quickly to coat.Spread mixture on lg. buttered jelly roll pan, pressing out evenly with buttered hands. While still warm, press on candy pumpkins, spaced about 1 1/2 in. apart.Cool and cut into squares.