Make and decorate cookies one day in advance. Prepare cookie dough following recipe directions. Use rolling pin to roll out 1/8 in. thick. Cut with heart cutter from set. Bake and cool cookies.
Prepare Color Flow icing following recipe directions. Tint red. Use tip 2 and full-strength red icing to outline heart. Use thinned red icing in a cut disposable bag to fill in heart; let dry 4 hours to overnight.
Make cupcakes. Prepare white batter following recipe directions. Tint portions of batter 1/3 red and 2/3 rose.
Place two-tone insert in baking cup-lined muffin pan. Use a cut disposable decorating bag to fill center ring of insert 2/3 full with red batter. Use a cut disposable decorating bag to fill outer ring of insert 2/3 full with rose batter. Remove insert and repeat until all cavities are filled. Remove insert. Bake and cool.
Decorate cupcakes. Prepare buttercream icing following recipe directions. Tint rose. Use spatula and rose buttercream icing to ice top of cupcakes smooth. Position heart sprinkles. Insert heart cookie.