In advance, using royal icing, make approximately 425 tip 16 stars in red and blue on waxed paper. Let dry. Assemble 8 fireworks sprays, 4 of each color. For each, gather 10 lengths of wire and fold in half. Cover the bottom 1 1/2 in. of folded end with florist tape. Attach stars to wires with dots of icing. Set aside.
Using buttercream icing, ice 1-layer 16 in. round cake smooth. Imprint feet of oval separator plate on center of cake top. Cut hidden pillars
to 4 in. lengths, insert in cake at marks. Position plate on pillars. Pipe tip 21 star bottom border. Position flag cake on cake board cut to fit and ice sides of cake smooth. Cover stripes and blue field on cake top with tip 16 stars. Add tip 21 white stars to blue field. Pipe tip 3 bead bottom border.
Position flag cake on separator plate. Insert flower spikes into round cake. Position fireworks sprays into flower spikes. Attach additional stars
to sides of round cake.
One of the most popular techniques, stars come in a range of sizes and styles. Experiment with open and closed stars for variation in look. The star technique is timeless and can be used as a classic border or as a stunning fill-in for the top of a dessert.