Rocky Road Fudge
["1 lb. confectioners sugar", "1 c. cocoa", "1/3 c. milk", "1 stick butter or margarine", "1 Tbsp. vanilla extract", "1 c. walnuts or pecans, chopped", "1 1/2 c. miniature marshmallows"]
["Butter an 8-inch square or round baking pan."]
["confectioners sugar", "cocoa", "milk", "butter", "vanilla", "walnuts", "marshmallows"]