Pour fruit in cast iron Dutch oven. Sprinkle dry cake mix over fruit. Dot margarine on top of cake mix. Cover tightly, set in coals of campfire, putting coals on lid also, and let cook until cake is lightly browned. Rotate Dutch oven one quarter turn every 15 minutes for even cooking, especially if the active fire is only on one side of the Dutch oven. Recipe can be halved easily.