I know it isn't sit down or special, but your options are really limited in MK for dining, but maybe Pecos Bills. It is pirate themed and has good food. Maybe you could to to the BOG for dessert after. They have really good desserts. I think you can go for dessert only, but that may be just at lunch. It's a fun atmosphere. I think that's what I would do, lunch at Pecos, then head over BOG for dessert.
a monorail ride away is O'hana, which I hear kids love.