Fudge Icing
["1 c. sugar", "3 Tbsp. cocoa", "1/8 tsp. salt", "1/3 c. milk", "1/4 c. butter"]
["Bring to full boil; boil 1 minute.", "Cool and beat in cold water until firm.", "Frost cake."]
["sugar", "cocoa", "salt", "milk", "butter"]