Preheat oven to 350F. Butter a 9"x5" loaf pan. Line the bottom with wax paper and butter the wax paper. You may also use two 8" round cake pans, line with butter wax paper.

In a large bowl, combine the flour, sugar, salt, baking soda, and cocoa and mix well. [Or, whiz in food processor.] Add the water and vanilla and beat until smooth. [Add and whiz.] Add the mayonnaise and beat until the batter is complete smooth and free of lum ps. [Add and whiz.] Transfer the batter to the pan and bake for 50 min for the loaf, 30-35min for t he layers, or until a cake tester comes out dry.

Cool for at least 20 min on a rack before removing from the pan. Remove from the pan and peel off the wax paper. The cake has such a rich fudgy taste that a little confectioners' sugar sprinkl ed over the top to give it a finished look is all that it needs.