Buy the 2015 Old Farmer's Almanac!
Both the USDA and theBoth the USDA and the National Center for Home Food Preservation say NOT to can pumpkin butter. It is also not recommended to can recipes that contain butter.

2015 Special Edition Garden GuideCooking Fresh with The Old Farmer's AlmanacThe Almanac Monthly Digital MagazineWhat the heck is a Garden Hod?