Bake and cool one-layer heart cake. Tint buttercream with rose icing color. Ice cake smooth with rose buttercream.
Using Rotary Cutter, cut 1 in. strips along length of Bright Pink Sugar Sheets! Using border punch with Scallop Border Cutting Insert, cut scallop design. Trim to 3/4 in high. Brush with piping gel and attach to bottom border of cake. Cut additional scalloped strips to fit around border, if necessary.
Cut one 8 in. heart from White Sugar Sheets! Using border punch with Scallop Border Cutting Insert, punch scallop design around heart shape. Using narrow end of tip 10, cut circles 1/2 in. from the outside edge. Brush with piping gel and attach to top of cake.
Make 19 ruffled ribbon roses, using 1 long x 8 in. wide strips made with Rotary Cutter and Bright Pink Sugar Sheets! Using scissors, trim base of each rose. Attach roses to top of cake with buttercream.