Straight from Grandma's recipe box comes a chocolate cake to be proud of. I'd never been a fan of mayonnaise in cake, so when Grandma first told me as a child that this cake used mayonnaise, it was hard for me to take that first bite. I remember fondly those days. And you'll remember the first time you bit into this wonderful chocolate cake with mocha frosting. The frosting calls for some instant coffee granules. If it's not something you keep on hand (most coffee drinkers don't), just get a 3 ounce jar at the local store. It's well worth the investment if you only use it in one batch of frosting!