Add all ingredients to a heavy bottomed sauce pot. Set over medium-high heat, stir ingredients together and bring mixture to a boil. Allow to boil for about 30-45 seconds and then reduce heat to a simmer.
Allow mixture to simmer for 30 minutes, uncovered. Frequently stir to ensure mixture does not burn at the bottom of the pot. By this time, the mixture should have thickened substantially and it should be very fragrant. It will continue to thicken as it cools.
Remove from heat and cool to room temperature. Transfer pumpkin butter to airtight containers, cover and store in the fridge until ready to use. Keeps for 1-2 weeks chilled.