2 cups flour
1 2/3 cup sugar
2/3 cup Hershey's unsweetened cocoa (or other high-quality chocolate)
1 teaspoon vanilla
1 1/4 teaspoon baking soda
1 1/4 teaspoon baking powder
3 eggs
1 1/3 cup water
1 cup Hellman's (Best Foods) real or light mayonnaise

Frosting
1 stick (1/2 cup) butter or margarine (we used butter)
2/3 cup Hershey's unsweetened cocoa powder
3 cups powdered sugar
1/3 cup milk
1 teaspoon vanilla extract
1/4 cup cocoa nibs (optional for decoration)