You can make your own brownies from scratch, but I let Betty Crocker make mine. I got this frosting recipe from a good friend of mine...it is divine.
1 ½ c. gran. Sugar
6 T milk
6 T margarine/butter
1 c. semi-sweet chocolate chips
Begin this recipe after your brownies are done. On medium-high heat, bring the sugar, milk & butter to a boil. Let boil for 30 seconds. Take off the burner and add the chocolate chips, stirring until you get a smooth consistency. Pour immediately onto the brownies.