Make princess features one day in advance. Make royal icing. Tint yellow, copper, brown, black and rose or violet. Reserve some white.
Tape princess pattern to cookie sheet; cover with parchment paper.
For crowns, use tip 1 and yellow icing to outline and pipe-in. Pat smooth with finger dipped in cornstarch.
For heads, use tip 12 and copper or brown icing to pipe ball on parchment paper-covered cookie sheet; flatten.
For torso, use tip 12 and rose or violet icing to pipe teardrop bodies on parchment paper-covered cookie sheet. Use tip 8 and rose or violet icing to pipe pull-out arms on bodies.
For hair, use tip 2 and brown or black icing to pipe hair on heads.
For flowers, use tip 225 and rose or violet icing to pipe drop flowers. Use tip 2 and white icing to pipe center dot.
Let all dry.
Make cupcakes. Prepare cupcake batter following recipe directions. Bake and cool cupcakes. Prepare buttercream icing. Tint portions rose and violet.
Assemble princesses. Use tip 2A and violet or rose icing to pipe mounds in center of cupcakes. Use tip 2A and violet or rose buttercream to pipe lines for skirt. Start at top of baking cup and end covering icing mound on cupcake. Repeat all around cupcakes.
For faces, use black edible color marker to draw eyes and mouth on head. Gently peel off top of body from parchment paper and insert into top of cupcake.
Using icing and cut parchment bag to attach flowers to princesses? hands.