Add 1 cup of water and ¾ cup of light brown sugar into a saucepan and simmer until all of the sugar has dissolved.
Whisk in ¼ cup of pumpkin puree and about 3 teaspoons of pumpkin pie spice (cinnamon, nutmeg, ginger, cloves, and allspice) and simmer on low.
Strain, add 1 tsp of vanilla extract, and allow to cool.