Simple Sugar Icing
- 1 pound (4 sticks) unsalted butter, room temperature
- 2 one-pound boxes confectioners' sugar, sifted
- 1/2 cup milk
- 1 tablespoon pure vanilla extract
- 1/4 teaspoon salt
- 1 tablespoon freshly squeezed lemon juice
Beat butter with electric mixer until light and fluffy. Beat in confectioners' sugar, 1 cup at a time, until smooth. Add milk, vanilla, salt, and lemon juice; beat until smooth. Refrigerate at least 1 hour.