Chocolate Mayonnaise Cake

Sift together flour, sugar, cocoa, baking powder and soda. Add ice water and vanilla. When mixed thoroughly, fold in mayonnaise. If you're using a mixer, fold the mayonnaise in by hand. Stir just til mixed; do not overbeat. Pour into a greased and floured (or Baker's Joy'ed) 13x9x2 pan and bake 30 minutes at 350 F. Cake is done when it starts to pull away from the sides of the pan and the top starts to crack; you can also use a toothpick test; do not overcook. Cool five minutes before removing from the pan. Butter Frosting 1/2 stick butter 1 lb powdered sugar (dash salt) 1/2 cup cocoa (optional) 2 tbsp (+) milk 1 tsp (+) vanilla Cream butter, 1/2 sugar, and salt. Add cocoa and 1 tbsp milk. Cream. Add sugar and milk til the consistency is right and then beat at mixer's highest speed. Frost cake immediately.