First, mix up the pumpkin spice:
2 tsp ground cinnamon
1 tsp ground ginger
1/2 tsp ground nutmeg
1/2 tsp ground allspice
Next, make the syrup:
1 ½ cups water
1 ½ cups sugar
4 tsp pumpkin spice
¼ cup pumpkin purée
¼ tsp vanilla extract
Bring water and sugar to boil in a small saucepan over medium heat. Whisk in pumpkin spice and purée, reduce heat to low, and gently simmer for 20 minutes until flavors meld and syrup thickens slightly.
Using fine-mesh strainer with cheesecloth, strain mixture into medium bowl, squeezing cheesecloth to extract as much liquid as possible; discard solids and stir in vanilla extract. (Pumpkin spice syrup can be stored in an airtight container for up to 1 week.)
Then, make the margarita:
2 oz tequila reposado (I use Hornitos)
1 oz fresh lime juice
1/2 oz Cointreau
1 oz pumpkin spice syrup
garnish: 1 cinnamon stick
If desired, make a spiced salt rim for the glass first. Mix some coarse kosher salt with a little bit of the pumpkin spices (at least cinnamon and/or nutmeg). Wet the edge of a 10 oz cocktail glass with lime juice, then dip the edge of the glass in the spiced salt. Add some ice to the glass.
Add the margarita ingredients to a shaker with ice. Shake until chilled then strain into the cocktail glass. Garnish with a cinnamon stick.

