Knox unflavored gelatin packets
Small (5-inch) balloons or water balloons
1 Tbsp vegetable oil
1 tsp light corn syrup
Blow up each balloon to the best size for your cupcake top. Double knot the balloons when tying to prevent any air from leaking. To cover 6 balloons, add 6 tablespoons cold water and 3 packets of Knox unflavored gelatin to a microwave-safe bowl (ratio is 2 parts water : 1 part powdered gelatin). Use a small whisk or a fork to mix in the gelatin with the water. Once mixed, set aside for 5 minutes. In this time, the gelatin will become a semi-firm sponge texture.
Place the bowl in the microwave and heat for 20-30 seconds, keeping a close eye on the gelatin to make sure it doesn’t begin to boil. Remove from the microwave and let sit for a couple of minutes to cool. Once cooled, use a spoon to skim the surface to remove the bubbles, as well as what I like to call the “muck” that can form on top during the heating process.