1/2 c. butter
1 c. brown sugar
4 tbsp. milk
2 c. powdered sugar

Melt butter in saucepan. Add brown sugar; boil over low heat for 2 minutes, stirring constantly. Stir in milk; bring to boil, stirring constantly. Cool to lukewarm. Gradually add powdered sugar. Beat until thick enough to spread. If icing becomes too stiff, add a little hot water.