There are a number of options.
You can still cook with them as normal, just add some sugar to taste. In the UK, we actually have cooking apples that are not sweet and are used extensively in cooking. I actually miss them now I've moved to Australia having grown up with them in the UK.
You can also make apple butter (which is a caramelised apple puree ). Same versions include apple cider vinegar and cinnamon, but my preferred version is litterally just apples and sugar. Once made, it is jarred/canned and used instead of jam. We love it in our porridge
Dry Apple juice is another option, as is dry cider. Dry being used in the same context as wine.