Lightly powder your hands with cornstarch and knead the pink fondant until it becomes soft and malleable.
Using one of the brushes, dip it into the cornstarch and lightly coat the silicon mold
Tear off a tablespoon amount of fondant and press into the tail mold. Allow to set for 5-10 minutes, then flip over the mold and carefully push out the fondant tail out of the mold.
Once all tails have been molded, spray the top of each tail with gold spray cake spray.
Allow to dry for about an hour.
How to Make Mermaid Frosting
Combine all ingredients in a stand mixer on medium speed. You can also use a hand mixer with a large non-slip mixing bowl.
If your frosting still seems powdery or chunky, add another tablespoon of heavy whipping cream and continue to mix until you have creamy stiff peaks.
Split frosting into two bowls.
Add 2-3 drops of pink gel food coloring to one bowl and 2-3 drops of blue gel food coloring to the second bowl. Mix each frosting until you have a bright pink and bright blue.
Scoop the pink frosting into a plastic piping bag and blue frosting into a second piping bag. For the pink frosting, you can simply trim an opening in the piping bag. For the blue frosting, we recommend a star tip.
Put it All Together:
Prepare cupcakes according to directions on box.
When cupcakes have cooled to room temperature, pipe a medium size dollop of pink frosting onto the top of each cupcake.
Use a butter knife to spread the frosting to cover the top of cupcakes.
Dip the top of the cupcake into the mermaid sprinkles, allowing excess sprinkles to drop back into bowl. Repeat as needed until most of the frosting is coated in sprinkles.
Pipe a dollop of blue frosting on top of each cupcake, in the center. Gently press a fondant mermaid tail into the frosting so that it is secure.