Pumpkin butter sounds like fall in a dish so I just had to give it a try with some of the Pumpkin Puree I made .Since the pumpkin butter is so dense you are not suppose to can it so you won't want to make a huge amount since it will be in the fridge and won't last forever.
I think this would be GREAT served right out of the slow cooker warm with gingerbread cookies or some pumpkin bread.
Pumpkin Puree or canned pumpkin (2 cans)
1/3 cup maple syrup
3/4 cup sugar
1/2 cup apple juice
1 lemon (juice only)
2 cinnamon sticks
3 teaspoons pumpkin pie spice
1/2 teaspoon salt
Put EVERYTHING in a slow cooker on low for 5-6 hours. I did stir it a couple times so it did not get "crusty) then turn it to high and vent the lid for 30 minutes. And that is all, so simple, and it is a mild flavor. If you like cinnamon (I do not) you might want to add some ground cinnamon too.