FOR THE FROSTING
1 1/2 to 3 teaspoons heavy cream
1 ounce cotton candy
1/2 cup (1 stick) unsalted butter, at room temperature
8 ounces confectioners' sugar
1/2 teaspoon vanilla extract
In a small bowl, pour 1 1/2 teaspoons of the heavy cream over the cotton candy to melt it; set aside.
In a large bowl, or the bowl of a standing mixer, cream together the butter and sugar until thoroughly combined. Stir in the vanilla and melted cotton candy. Beat on medium high until light and fluffy, about 45 seconds, adding the remaining cream, if necessary.