Position an oven rack as close to heating element as possible and preheat broiler. Brush a 9 inch glass pie plate with some of the melted butter.
Arrange pineapple slices over bottom of pie plate. Drizzle with remaining melted butter and sprinkle with lime juice. Sprinkle brown sugar over slices. Broil until the brown sugar is bubbling, 2 to 2 1/2 minutes. Sprinkle coconut over top, return to broiler and broil til golden, 15 to 30 seconds. Watch carefully because the coconut will burn quickly after it browns.
Put 2 pineapple slices in each of 4 dessert bowls, top with 2 small scoops of ice cream and some of the juices from pie plate and serve at once.
Fresh pineapple is now available pre peeled and pre sliced at the supermarket, great for quick desserts like this tropical gratin. Let it come to room temperature before you assemble the dessert, so it warm up sufficiently under the broiler. Serve at once