1Heat oven to 350°F. Grease bottom of 2 (8-inch) heart-shaped foil pans. Make cake batter as directed on box. Pour into pans. Bake as directed on box for 2 (8-inch) rounds.
2Cool 10 minutes. Run knife around sides of pans to loosen cakes; remove cakes to cooling racks. Cool completely, about 1 hour.
3For bride cake, place 1 cake layer on serving plate. Frost cake with white cupcake icing, leaving V-shaped area at top of cake. Frost V-shaped area with pink cupcake icing. Pipe lace design on dress and V-shaped edge of dress with white cupcake icing, using writing tip. Use white decorating decors to make pearl necklace.
4For groom cake, place remaining cake layer on another serving plate. Frost cake with black decorating icing, leaving V-shaped area at top of cake. Frost V-shaped area with white decorating icing. Pipe black buttons and lapels with black decorating icing. Pipe red bow tie on shirt with red decorating icing. Store loosely covered at room temperature.