Melt in a medium saucepan:

3 tbsp. butter

Stir in:

2 tbsp. cocoa until dissolved

Add:

1 1/2 c. confectioners' sugar
2 tbsp. milk
1 tsp. vanilla

Stir until smooth. Add more milk if necessary to make a soft spreading consistency. Frosts one 13 x 9 inch pan of brownies. Let set until firm.