1/3 cup canned pumpkin puree (be sure it's plain pumpkin – not pumpkin pie filling)
Add all ingredients in an ice-filled mixing glass and stir vigorously for about 20-30 seconds. Strain into either an empty coup or a rocks glass with one large ice cube. Garnish with a rosemary twig (if you want to get fancy smoke/char the rosemary first. I like fancy.)
Pumpkin spice syrup:
Combine water and both sugars in a pot over medium low heat and simmer until sugar dissolves.
Add in remaining ingredients – cinnamon through pumpkin, and stir carefully (the sugar water will be very hot!!) but thoroughly to combine.
Reduce the heat to low and simmer for about 10-15 minutes, stirring every few minutes. Do not let the mixture boil.
Turn off the heat and let cool for 20 minutes on the stove.
Strain through a fine mesh strainer and store in the refrigerator.