Grandma'S Microwave Fudge
["1 (16 oz.) box confectioners sugar", "1 stick butter", "1/4 c. milk", "2/3 c. peanut butter"]
["Melt butter and peanut butter in large bowl.", "Remove from microwave; add sugar and milk until creamy and smooth.", "Place in microwave on high; stir after 30 seconds.", "Pour into buttered pan and let cool."]
["confectioners sugar", "butter", "milk", "peanut butter"]