1. Combine pumpkin, apple juice, spices, and sugar in a large saucepan and stir well. Bring mixture to a boil, covered with lid ajar (I prop it with a wooden spoon). Reduce heat to low-medium and simmer, covered with lid ajar, for 35-45 minutes, stirring frequently. Be careful as the mixture bubbles and pops!
2. Remove from heat and let it sit for a few minutes before removing lid. Adjust spices to taste. Stir in lemon juice. Once cool, pumpkin butter can be kept in an airtight container in the fridge for up to 3 weeks. Makes enough to fill one large mason jar or about 3.5 cups.
Note: canning is not reccomended.