Sift together flour, baking soda, sugar, salt, and cocoa. Place the sifted ingredients in a pan square cake pan. Make three holes in the mixture, and into each hold put in the following:
1 Tbsp. Vinegar
1 tsp. Vanilla
5 Tbsp. Butter
Pour 1 cup cold water over top and mix well. Bake in a 350 degree oven for 30 minutes or until toothpick comes out clean. This is good served warm with ice cream.