Brew espresso and let it cool to room temperature.
Fill the cocktail shaker with ice cubes.
Pour vanilla vodka, cooled espresso, coffee liqueur, and vanilla syrup into the shaker.
Shake hard for 20-30 seconds until the shaker feels very cold.
Double strain the mixture through both strainers into a chilled martini glass.
Place three coffee beans on top as garnish.
Notes
The espresso must be fresh and cooled before mixing. Hot espresso will melt the ice too quickly and make the drink watery.Store-bought vanilla syrup works fine, but you can make your own by mixing equal parts sugar and water with a split vanilla bean.Cold brew coffee can replace espresso in a pinch, but the drink won't have the same rich crema on top.The cocktail should have a nice foam layer when properly shaken. If it doesn't, try shaking longer or using fresher espresso.