Bake and cool cake; trim to 1 1/2 in. high. Cut treats with a knife using smallest round cutter from set as a guide. Ice bottoms with melted candy; place on waxed paper-covered board and chill until firm. Cover treats with melted candy; chill until firm. Fill a shallow bowl with pink sugar. Using melted candy in cut parchment bag, pipe line around bottom edge of treat. Place treat in bowl and coat edge with sugar. Brush off excess sugar. Repeat for top edge, then center. Attach rose with melted candy.