1. Prepare cake, 1 recipe at a time, using 2 jellyroll pans; bake as directed.
2. Cut out 24 cake layers, using a 3-inch scalloped cutter.
3. Sandwich together 2 layers with a small amount of Buttercream Frosting; repeat with remaining layers. Place each cake on a wire rack over a shallow bowl or pan.
4. Prepare Poured Fondant, 1 recipe at a time; tint with food coloring paste, if desired. Quickly pour fondant over cakes, completely covering tops and sides. Reheat excess fondant, if necessary. Continue until cakes are evenly coated. Let dry before decorating.
5. Insert a coupler into a large decorating bag. Fit coupler with metal tip #1, and fill bag with remaining frosting. Pipe bridesmaids' initials on center of cakes, if desired. Pipe a shell border with metal tip #16 around top and bottom edges of cakes.