4 sticks unsalted butter, softened
6 cups sifted confectioners' sugar
1/2 teaspoon vanilla extract
1 pinch of salt
Put butter in bowl of an electric mixer. Beat on medium-high speed until pale and creamy, about 2 minutes. Reduce speed to medium; add sugar 1/2 cup at a time, mixing well, about 5 minutes total. Add vanilla and salt. Raise speed to medium-high; beat until smooth, about 1 minute more.
For colored buttercream, stir in food coloring, drop by drop, until desired shade is achieved.
Makes 5 1/4 cups