This just happened to come up on my Youtube home page, probably because my wife and I were looking at making apple butter before we did it. Wife was going to use two or three crock pots then decided she had a roaster that was big enough to do it all in one batch so used it instead. But what she did appears to be very similar to what this lady did to make apple butter and even the end result looks pretty similar including the pressure canning at the end. Didn't add any extra sugar though. I just skipped through it watching bits and pieces and did not watch the whole thing though.

https://www.youtube.com/watch?v=JW53DwJfGtk#mce_temp_url#