Delicious Dessert Quickie

Blend the sugar, cocoa and water in a 13x9x2 baking pan. Sprinkle with marshmallows. Prepare cake mix according to package directions, but add vanilla to the batter. Spoon the batter over the mixture in the pan. Top with nuts. Bake at 350(F)for about 50 minutes. Allow to cool slightly, then cut into serving size pieces, sauce side up.