In advance, make approximately 18 tip 104 ribbon roses with tip 12 bases using dark rose royal icing. Make extras to allow for breakage and let dry 1-2 days.

Spatula ice 1-layer cake smooth in light rose buttercream icing.

Roll out fondant 1/8 in. thick. Using pan as a pattern, cut out heart shape 1 in. smaller than pan. Using large opening of tip 1M, cut scallops along edge. Using small opening of tip 6, cut holes in scallops. Position fondant heart on cake, securing with dots of icing. Attach roses with dots of buttercream icing.

Using white buttercream icing, pipe tip 16 shell bottom border. Pipe tip 125 ruffle over shell border.