Combine water and sugar in a medium pot over medium-high heat. Cook, stirring occasionally, until sugar has completely dissolved. Add the cinnamon sticks, then whisk in remaining ingredients. Cook for about 5 minutes, stirring frequently, but do not let the mixture come to a boil (reduce heat if necessary).

Remove from heat and allow to cool for about 10 minutes. Strain syrup through cheesecloth into an airtight container. Store in the refrigerator.

To make a pumpkin spice latte, simply add about 1½ to 2 tablespoons of syrup for each shot of espresso. For an iced latte, stir together syrup and espresso before adding desired amount of cold milk. For a hot latte, add about 5 ounces of steamed milk and stir to combine. Taste and adjust syrup accordingly. Top with whipped cream and sprinkle with cinnamon or nutmeg, if desired.