Combine a large can of crushed pineapple (with juice), a 6-ounce package of vanilla pudding (not instant) and 1 cup of water in a saucepan.
Bring to a boil, stirring. Pour the mixture into a 12x13x2-inch pan and chill until firm.
Prepare 1 package of white or yellow cake mix according to box directions, and pour
over the chilled pineapple pudding. Bake in a pre-heated 350 degree oven for 30 minutes.
Cool for 15 minutes before inverting on plate.