I love a moist and delicious cake! When I made these Gobs ( whoopie pies), I wanted them to be moist and delicious too. So instead of oil or butter I decided to use mayonnaise. Using mayonnaise keeps these very moist, however you can't taste it at all. I never even told the kids until a week later and they had no clue! I decided to pair these up with a creamy peanut butter icing and it was the perfect combination. I don't like the icing to be too sweet, but you can add more sugar if you prefer. This recipe comes together in a snap and you'll most likely have all the ingredients at home.