Peanut Butter Icing
["2 c. sugar", "1 stick margarine", "1 small can evaporated milk", "1 tsp. vanilla", "3 heaping Tbsp. peanut butter (creamy or crunchy)"]
["In medium saucepan, combine sugar, margarine and evaporated milk.", "Stir to mix well.", "Bring mixture to a boil, stirring constantly.", "Boil for 2 minutes or to soft ball stage on candy thermometer.", "Remove from heat; add vanilla and peanut butter and stir vigorously.", "Pour icing over yellow sheet cake.", "Let set to allow icing to harden."]
["sugar", "margarine", "milk", "vanilla", "peanut butter"]