French Silk Frosting

2 2/3 cups confectioners' sugar
2/3 cup butter, softened
2 (1 ounce) squares unsweetened chocolate, melted and cooled
3/4 tablespoon vanilla extract
2 tablespoons milk

In a medium bowl, blend confectioners' sugar, butter, melted chocolate and vanilla extract on low speed. Gradually add milk, beating until smooth and fluffy.