The unexpected ingredients in this recipe are the mayonnaise and the instant coffee, both of which help to make the cupcakes extra moist and chocolate-y. This recipe is like an old-fashioned mayonnaise cake, and is one that I have made many times because it is so good. I have used it for sheet cakes, as in Shirl's Brooklyn Blackout Cake, for vintage layer cakes, and for these cupcakes. You just can't go wrong with this recipe.