toothpick inserted in center comes out clean. Remove pan from oven and sprinkle marshmallows evenly over cake. Return to oven for 10 minutes or until marshmallows are melted. Cool in pan on wire rack. Spread with Mississippi Mud Icing. Chill before cutting into squares. MISSISSIPPI MUD ICING ~~~~~~~~~~~~~~~~~~~~~ 1 cup (2 sticks) butter or margarine, melted one third cup cocoa half cup evaporated milk 4 cups sifted confectioners' sugar (about 1 pound) 1 teaspoon vanilla half cup chopped pecans Combine butter and cocoa in mixing bowl; add evaporated milk. Gradually stir in sugar; beat until smooth. Stir in vanilla and pecans; blend thoroughly. ----