Bake and cool one-layer cake. Place on foil-wrapped cake board. Ice smooth with rose buttercream.
Tint 7.5 oz. fondant brown and 3 1/2 oz. rose. Roll out brown, rose and white fondant 1/8 in. thick. Using Rotary Cutter, cut 18 strips, 2 long x 1 in. wide, in each color. Attach to cake sides with damp brush, alternating colors.
Roll out brown fondant 1/8 in thick. Cut a rectangle, 6 high x 9 in. wide. Trim to fit top left corner of cake. Using punch with Small Heart Cutting Insert, cut out heart, 1 in. from top edge; reserve. Position rectangle on cake.
Roll out white fondant 1/8 in. thick. Cut a rectangle, 6 high x 9 in. wide. Position on center of cake. Using border punch with Lace Border Cutting Insert, cut border pieces, two 9 1/2 in. long and two 6 1/2 in. long, from remaining rolled white fondant. Trim to 1/2 in. high. Position around rectangle.
Brush lace border with white Pearl Dust. Using tip 3 and rose buttercream, pipe bead border to cover seam between rectangle and lace border.
Using letter cutters from set, cut "LOVE." Brush letters with orchid pink Pearl Dust and position on cake.
Position reserved heart at bottom right corner of white rectangle. Roll out remaining rose fondant 1/8 in. thick.
Roll out remaining white fondant 1/8 in. thick. Cut two strips, 11 1/4 long x 1 1/2 in. wide, and two strips, 15 1/4 long x 1/2 in. wide. Using border punch with Lace Border Cutting Insert, punch lace design across strips. Trim all strips to1/2 in. wide. Brush strips with white Pearl Dust.
Attach lace strips to bottom of cake using a damp brush. Using tip 3 and rose buttercream, pipe bead border around cake.