1/2 cup butter
1 cup brown sugar
1/4 cup milk
1 3/4 to 2 cups sifted powdered sugar
Melt butter in a medium saucepan, add brown sugar and bring to a boil. Over low heat, boil for 2 minutes, stirring constantly. Stir in milk, bring mixture back to a boil, stirring constantly. Cool to lukewarm, then gradually stir in powdered sugar. Beat until thick enough to spread. If frosting is too stiff it can be thinned with a little hot water.