Combine ingredients in jar with ¾ cup mayonnaise, ½ cup cold water, ½ cup brewed coffee and 1 teaspoon vanilla. Stir until smooth and pour into greased and floured pans (two 8 inch cake pans, one 9x13 baking pan or cupcake tins).
Bake cake for 30 to 40 minutes or bake cupcakes for 16 minutes. Allow to cool before frosting