Apple cheese. It is made in Lithuania, and probably other countries as well - I have had quince cheese/paste in France, same idea.
My mother has 3 thrift store slow cookers for the purpose. Either peel and core, or plan to put through a food mill. Cook on high until they get saucy, food mill to get rid if seeds and peels if needed, then back onto the slow cooker on low keep on low with the lid cracked for several days until it is dry
enough to pull away from the sides. The volume goes was down, and we usually add more apple slices for the first day or two to fit more in. Once it pulls away from the sides, shape it on wooden boards, cover with a clean cloth, and put in a warm place with good airflow. You can probably do it with an
oven or
wood stove too, even
solar oven, as long as you can keep the heat low enough to dry it without scorching. For us, the slow cookers put a bit of heat in the house in the cool dry season before it is cold enough to fire up the stove.
You can add some spices at the sauce stage if you like, and it can be done with other fruit. Quince is delightful, though I think it needs sweetener. Pear and asian pear are ok, but a bit grainy.