Ingredients
4 1/2 sticks room-temperature unsalted butter
6 3/4 cups confectioners' sugar
1 tablespoon plus 1 1/2 teaspoons whole milk
1 teaspoon pure vanilla extract
Preparation
Beat butter and 1 1/2 cups sugar with a mixer on medium speed until pale and fluffy. Reduce speed to medium-low; gradually add an additional 5 1/4 cups sugar. Raise speed to medium-high. Add milk and vanilla. Continue to beat until pale and fluffy, about 3 minutes. Store at room temperature until ready to use (up to 2 days).