If possible, use clear vanilla extract for the frosting.
I found the marshmallow frosting to spread almost too easily (meaning it was hard to keep it from dripping off the cake), which is why I recommend mixing the coconut into the frosting before piping or spreading. If your frosting is just too stiff, add a tiny bit of milk to reach your desired consistency.
I would have liked the frosting to be an even brighter white; next time, I'll definitely add white food coloring to really punch of the "coconut".
DARK CHOCOLATE & MARSHMALLOW COCONUT CUPCAKES
INGREDIENTS
Cake
1 box Duncan Hines Dark Chocolate Fudge cake mix
1 box Hersey's Special Dark instant pudding mix
4 large eggs
1 cup sour cream
1/2 cup milk
1 tablespoon vanilla extract
1/4 teaspoon salt
Frosting
1/4 cup softened non-salted butter
7 ounces marshmallow creme
1 teaspoon coconut extract
1 teaspoon vanilla extract (clear, if possible)
3 cups powdered sugar
3/4 cup shredded coconut
DIRECTIONS
Cupcakes
Preheat oven to 350F.
Line cupcake pan.
Combine all ingredients in stand mixer and beat until combined.
Fill cupcake liners 2/3 full.
Bake 18-22 minutes (until toothpick comes out clean).
Remove from oven and transfer cupcakes to wire rack to cool.
Frosting
Combine all ingredients in stand mixer and mix until combined.
Add shredded coconut and pipe or spread on cupcakes.
Decorate with fondant hearts or fun celebratory flags (as shown).