To decorate: Create a cavity by cutting a cone-shaped piece out of the top of each cupcake. Fill each cupcake with 1 teaspoon lemon curd; replace the pieces. Frost the cupcakes and top each with half of a lemon-slice candy.
To decorate: Frost the cupcakes and top each with one 1-inch piece red licorice twist (for the firecracker stick), one 1-inch piece black shoelace licorice (for the fuse), and ½ teaspoon Pop Rocks candy (for the sparks).
To decorate: Frost the cupcakes. Top each with 1 halved marshmallow (cut-side up) sprinkled with pink decorating sugar (for the ears), 2 miniature chocolate chips (for the eyes), 1 peanut butter chip (for the nose), and 6 chocolate sprinkles (for the whiskers).