Caramel Frosting

1/2 c. butter
1 c. packed brown sugar
1/4 tsp. salt
6 T. milk
3 c. powdered sugar

Melt butter.  Stir in brown sugar and salt.  Bring to a boil and boil 2 minutes, stirring constantly.  Remove from heat and add milk while stirring.  Return to heat and bring to a boil.  Remove and allow to cool 20 minutes.  Stir in powdered sugar.