Applesauce, of course! You don't even have to peel them if you don't want to. Quarter and core them (or use an apple slicer if you have one), put them in a heavy saucepan with an inch or so of water at the bottom, watch so they don't burn (you can put in more water if you're not a good watcher, just make sure to drain some out afterward), then mash with a potato masher. Add sweetener to taste. Delicious!