Caramel Icing
["2 c. brown sugar, packed", "1 c. white sugar", "1 c. cream", "1 stick margarine", "1 tsp. vanilla"]
["Boil brown sugar, white sugar and cream until forms firm ball when dropped in water. Remove and add margarine and vanilla. Beat until spreading consistency."]
["brown sugar", "white sugar", "cream", "margarine", "vanilla"]