Combine the pumpkin purée, dark brown sugar, maple syrup, ground cinnamon, ground ginger, ground cloves, ground allspice, water, and vanilla extract in a heavy-bottomed saucepan. Stir thoroughly to mix well.
Heat the mixture on medium-high until it boils. When boiling, lower the heat and let it simmer for around 20 minutes, stirring frequently, until the butter thickens and achieves a smooth consistency.
Take off the heat and allow to cool completely before either serving or refrigerating.