1/2 c. butter
1 c. brown sugar, packed
1/4 c. cream (can use evaporated milk)
1 3/4 to 2 c. powdered sugar

melt butter in saucepan. Add brown sugar and bring to a boil over low heat and cool exactly 2 minutes. Stir continuously. Take off heat. Add powdered sugar and cream and beat with electric mixer until cool. If need, add more powdered sugar.