I don't know what it was called (server said we had to try) but it was one of the best desserts I have ever eaten..........we didn't leave a morsel.......
Sorry to say that the Dad's Super Sundae has been replaced by the very scaled down Brownie Sundae which is about a third of the size of Dad's Super Sundae (much like the helping of meatloaf).
I remember my eyes bugging out of my head when we ate there and our table ordered the Dad's Super Sundae. It was huge but between DH, two of our friends and myself we were able to put it away and then roll out of the restaurant.
My husband and son got the PB&J shakes as their drinks on the DDP when we went twice in September. They absolutely loved them! We got the Brownie Sundaes for dessert.