It's called "My Only Wish" [...for Christmas Is You]. Can you guess exactly what it sounds like with the exact same tune and basically the exact same lyrics with just a few words switched? "We put it together pretty quickly," Jessica explains. Indeed. "Quickly" here being what? Eight, nine seconds? Plz hold as I record "Over There in a Manger," "Two Other Kings and I," "Cool King Wenceslas," "Noel No. 1," etc. etc. etc. I'm going to be a famous musician!
(It gets started at 2:40.)