Make cookies. You will need two cookies per treat. Prepare dough and roll out dough 3/16 in. thick. Cut using round Comfort-Grip.
Invert whoopie pie pan and spray with vegetable pan spray. Drape dough over every other pan cavity, pressing to smooth surface. Bake 10-14 minutes, or until firm and golden brown. Cool pan on cooling grid 10 minutes. Carefully loosen bottom edges of pan using spatula.
Fill treats. Fill one cookie with candy-coated chocolate candy.
Make piñata treats. Prepare royal icing. Tint brown; reserve some white.
Use tip 8 and white icing to pipe a line around rim of candy-filled cookie; attach second cookie. Use tip 8 and white icing to pipe an additional line around edge.
Decorate football trim. Use football cutter from set and black edible color marker to make a pattern on parchment paper. Use piping gel and a cut parchment bag to outline pattern; transfer onto cookie.
Use tip 3 and brown icing to pipe football. Use tip 16 and brown icing to fill in football with stars. Use tip 16 and white icing to pipe laces.
The star tip creates the most celebrated, easily accomplished decorations! The serrated edges of the star tip make ridges in the icing as you squeeze it out. Because fill in requires so much piping from the same bag, keep replenishing icing in bag.