1/2 c. butter
1 c. brown sugar, packed
1/4 c. milk
1 3/4 to 2 c. powdered sugar

Melt butter. Add brown sugar. Boil over low heat for 2 minutes, stirring constantly. Stir in milk. Stir until it comes to a boil. Cool to lukewarm. Gradually add powdered sugar. Beat until spreading consistency. If frosting becomes too stiff, add a little hot water.