Homemade applesauce is a really easy project to do in a crock pot. I use three big slowcookers to help make it worthwhile to do a bunch at once when canning, but it could just as easily be made in a medium crock pot, for a small amount for immediate eating.
First wash the apples really well, rinsing them thoroughly. I like to use a combination of different kinds of apples, some tart and some sweet, to have a good layered flavor in the finished sauce.
Quarter them, removing stems and trimming away any bruises or worm spots or icky blossom ends, and pile them into the slowcooker.
I start them on low and turn them to high after an hour or so, so that they'll release some juice before they get too hot and won't burn. They take about five hours to cook up until they're completely softened and mushy.
I use my victorio strainer to smash them into sauce and separate the skins and seeds from the rest of the sauce. A food mill will work for this too, but I really recommend one of these if you plan to do much canning at all, since it's great for all sorts of things, and only costs about twenty or thirty dollars more than one of those food mills does, and is so much easier to use.
This is the waste that comes out of the end, made up of the tough core parts, skins and seeds. The chickens cannot get enough of this. This slimy mush is honestly, like, delicacies for chickens.
I put the sauce back into the crock pot on high, to keep it very hot for the canning. Follow the instructions in the Ball book for canning applesauce. Quarts are processed in a hot water bath for twenty minutes.
I also add a tablespoon of lemon juice to each quart, since the applesauce recipe from the Ball book calls for that when making applesauce in a pot. I don't know if that's to prevent browning or to make it more acid, so as to make it keep better. It doesn't make it taste any different, so I just put a tablespoon in each quart before I fill it with sauce, just to better safe than sorry.
My three crockpots make 8-9 quarts of sauce, and they don't have to be babysat the way that a pot on the stove does, so I'm pretty happy with this method.