The Historic Russian Recipe That Turns Apples into Marshmallows
atlasobscura.com
atlasobscura.com
The long slow bake from this recipe is also how you make apple butter.
"I used to be convinced that the word ‘pastila’ derived from the words you mention below, but the deeper I dug, the more I came to believe that its etymology is more likely the old Russian стьлати — to spread out, which is the root of the word ‘postel’ as well. The derivation has to do with the technique of spreading the fruit paste into sheets to dry, and it ultimately makes more sense to me than the expected connection to various words related to ‘pastilla.’ One of the problems with researching food is that most of the people who compiled dictionaries were not fluent in in the kitchen, so I don’t entirely trust Fasmer, for instance, who states that the connection to ‘postel’ is a folk etymology."