Ensure the espresso is freshly brewed for the richest flavor. Let it cool slightly before use.
In a cocktail shaker, combine the espresso, vodka, coffee liqueur, and pumpkin spice syrup.
Add ice cubes to the shaker, seal it, and shake vigorously for about 15 seconds.
Strain the mixture into a chilled martini glass. Garnish with a cinnamon stick or star anise for an added touch of autumn.