Lightly powder your hands with cornstarch ,and work the fondant until it becomes soft.
Using a food safe paint brush, coat the silicon mold with corn starch.
Tear off a tablespoon of fondant and place into the tail mold.
Let sit for 5-10 minutes before flipping over the mold and carefully pushing out tails. Spray with silver cake spray. Allow to dry for one hour.
Repeat steps for the Seashells
For the Cupcakes
Preheat oven to 350 degrees F ,and line cupcake pan with paper liners.
In a medium bowl, combine the cake mix, butter, and milk, and mix until combined.
Using a medium ice cream scoop, scoop the batter into the cupcake liners until about ¾ of the way full. Bake in the oven for about 21 minutes. Cool completely.
For the Frosting and Decorations
In a large bowl, cream butter and vanilla until light and fluffy. Add powdered sugar a little at a time. Add heavy cream as needed to reach your desired consistency.
Reserve 1 cup of frosting and add a few drops of teal food coloring. Place teal frosting into a piping bag fitted with the star tip.
Scoop some of the white frosting onto the cupcake and smooth out using an angled spatula.
Dip the cupcake into the brown sugar to make a sand effect.
Pipe a dollop of the teal frosting onto the center of the sand. Place the tail into the teal frosting. Place seashells around tail.
Randomly place the nonpareils around the tail and seashells.
Ingredient Notes and Shopping Tips
Fondant: Look for moldable fondant, also called rolled fondant.
Cornstarch: This helps make our fondant easier to work with. You can also use powdered sugar here. Avoid flour which you don't want to eat without cooking.
Brown Sugar: If you don't want to use brown sugar: crushed vanilla wafers, graham crackers, or even shredded coconut would be similar in color.
Food Coloring: Use gel food coloring if possible for more vibrant colors.
Tips and Tricks
Ice Cream Scoop: Fill cupcakes with an ice cream scoop to ensure they are uniform size, and that will bake at the same rate.
Cupcakes are done when they spring back when lightly touched. You can also insert a toothpick into the center. It should come out clean or with just a few moist crumbs. If you see cake batter continue baking a few minutes at a time.
Make-Ahead: You can make the cupcakes and fondant decorations up to 2 days in advance. Assemble just before serving.
Store leftover fondant tightly covered at room temperature for up to 2 months.