In a small pot, bring the brown sugar and water to a low simmer.
Add the pumpkin pie spice and stir frequently for 2 minutes.
Remove the pot from the heat and add in the vanilla extract. Stir until thoroughly combined.
Once cooled, pour the syrup into a storage container such as a mason jar or old syrup bottle.
After sitting for a couple of days the spice can begin to settle at the bottom. If desired you can strain the spices once the syrup is cool or simply shake or stir before use. I usually strain my syrup after a couple of days of curing in a mason jar.