In a Dutch oven, combine marshmallows and cubed butter. Cook and stir over medium-low heat until melted. Remove from the heat; stir in cereal. Press 4 cups into a greased 9-in. round pan. Form remaining mixture into a 5-in. diameter x 6-1/2-in. tall cylinder; place on waxed paper to cool.
For frosting, in a large bowl, beat softened butter until fluffy; beat in confectioners’ sugar and vanilla until smooth. Beat in marshmallow creme until light and fluffy.
Unmold cereal mixture from 9-in. pan and place on a cake plate. Place 3 cups frosting in a small bowl; beat in red food coloring until smooth. Frost top and sides of 9-in. cake with 1 cup red frosting.
Place 1 cup white frosting in a small bowl; beat in blue food coloring until smooth. Frost bottom 2-1/4 in. of the cylinder with blue frosting. Place cylinder on cake. Frost the rest of the cylinder with red frosting.
Cut a small hole in the corner of pastry or plastic bag; insert #48 basketweave tip. Using white frosting, pipe stripes on sides of hat. With a #7 round tip, pipe trim.
Using a 1-1/2 in. star cookie cutter, press a row of stars onto hatband. Fill in stars with white frosting using the #7 tip. Yield: 24 servings.
Nutritional Facts: 1 piece equals 462 calories, 24 g fat (7 g saturated fat), 10 mg cholesterol, 181 mg sodium, 60 g carbohydrate, trace fiber, 1 g protein.