The firm texture of this buttercream frosting helps to keep candy decorations in place.

3 cups (6 sticks) unsalted butter, softened

9 cups sifted confectioners' sugar

1 teaspoon vanilla extract

Beat butter in the bowl of an electric mixer fitted with the paddle attachment on medium high speed until pale and creamy, about 2 minutes.
Reduce speed to medium. Add the confectioner's sugar, 1/2 cup at a time, beating well after each addition and scraping down the sides of the bowl with a spatula as needed, about 5 minutes total. After every 2 additions, raise speed to high, and beat 10 seconds to aerate the frosting. Add vanilla, and beat until buttercream is smooth.