Gather your materials!
Mix the gelatin packet with one cup of boiling water.
Pour one cup of tonic water into the gelatin mix. Chill the gelatin to room temperature or a bit cooler, but don’t let it set.
Dunk the frosted ends of the cupcakes into the gelatin glaze, then place the cupcakes in the freezer to let them set. Repeat five to six times.
In a dark room, shine the UV light on the cupcakes to see the frosting glow!
Tonic water makes your cupcakes glow because of a chemical in it called quinine. People originally put quinine in drinks because it can help to prevent malaria. Quinine also turns out to be fluorescent, which means that it glows when it’s hit by ultraviolet light. With just a bit of tonic water, your cupcakes will really stand out under a blacklight!