Preheat oven to 350°. Press cookie dough into an ungreased 13x9-in. baking pan. Bake 10-14 minutes or until edges are lightly browned and center is set. Sprinkle with marshmallows; bake 4-5 minutes or just until marshmallows are puffed. Cool 5 minutes.
Meanwhile, in a small saucepan, combine chocolate chips, peanut butter and butter. Cook and stir until chocolate is melted and mixture is smooth. Remove from heat; stir in cereal and peanuts. Drop by spoonfuls over marshmallows; gently spread over the top. Cool and cut into bars.