Vanilla Marshmallow Butter Cream Icing

Makes 3 cups.

1 cup unsalted butter, softened
1 (7 ounce) jar marshmallow cream, such as
    Marshmallow Fluff or Marshmallow Creme (2 cups)
1 cup confectioners' sugar
1 teaspoon vanilla extract

Beat butter in a medium bowl with mixer on medium speed until creamy. Beat in marshmallow cream. When well blended, beat in confectioners' sugar and vanilla extract. Increase speed to high and beat 3-4 minutes until fluffy.