My favorites are:
-Chai Cream at Sanaa
-Frozen chocolate bananas from the carts
-Zebra Domes from Boma
-Green Tea Pudding from Teppan Edo (looks gross, tastes great!)
I'll up the ante and say that the Ooey Gooey Toffee Cake at Liberty Tree Tavern is the BEST dessert I've ever had IN MY LIFE! There just really aren't words...