Grease 2 (9-inch) round cake pans lightly; set aside. Microwave butter in 4-qt. microwaveable bowl on HIGH 45 sec. or until melted. Add marshmallows; toss to coat. Microwave 1-1/2 min. or until marshmallows are completely melted, stirring after 45 sec. Add cereal; mix well.
Remove 1 cup of the cereal mixture; shape to resemble the snowman’s hat. Press remaining cereal mixture evenly into prepared cake pans. Cool completely.
Remove cereal rounds from pans; place on large cutting board or serving platter to resemble head and body of snowman. Place hat on the snowman’s head. Decorate with fruit roll to resemble the scarf and hat band, and with fruit snacks to resemble eyes and nose. Add cookies for the buttons. Gently stretch soft candy into 2-inch length and use for mouth.