This icing is DELICIOUS and so easy. In a saucepan over low heat cook 1/2 cup butter, cubed and 1 cup of brown sugar until melted and smooth. Stir in 1/4 cup of evaporated milk and bring to a boil, stirring constantly. Cool to room temperature. Stir in 2 cups of powdered sugar and a dash of vanilla extract and it will be perfect for any type of cake.