Cut a fresh pineapple into ½ or ¼ inch rings, leaving the core in. Soak the slices in Amaretto, just enough to cover, for about a week. Orange juice could also be used as an alcohol free marinade. Put the pineapple directly on the cooking grids (on the warming tray) of a hot grill and heat for 5 minutes. Remove the pineapple; turn the grill down to low, and lightly toast slices of pound cake or angel food cake. Slice the pineapple into chunks, place on the cake and drizzle with the reserved marinade.