Is it possible to make something like cake, pudding or crumbles (like an apple crumble) in a crock pot? I'd love to make a big batch of something and portion it out for the week instead of standing over the stove but I'm guessing pudding would develop a skin on top and crumbles wouldn't get crispy on top while cake would likely burn on the bottom. Have you tried to make slow cooker desserts and if so, how did they turn out?