1 day in advance: prepare silver trims. Use mold to make white fondant bows for each treat. Place on parchment-covered boards. Paint with silver Pearl Dust/lemon extract mixture. Also paint one marshmallow per treat with mixture. Let all dry.
Bake and cool cake using firm-textured batter, such as pound cake. Cut into 2 in. squares. Tint remaining fondant rose. Prepare and cover treats with rolled fondant. Attach marshmallow and bow with thinned fondant adhesive.
For labels, use rotary cutter to cut 1 1/2 in. squares from white edible paper. Use punch with medium heart insert to cut bright pink edible paper hearts. Attach to white squares using edible adhesive. Print initial with black edible marker. Attach to treat with edible adhesive.