Add 1.5 oz (45 ml) vodka to a cocktail shaker
Add 1 oz (30 ml) espresso (freshly brewed and cooled)
Add 0.75 oz (22 ml) coffee liqueur (Kahlúa or similar)
Add 0.5 oz (15 ml) simple syrup (optional, to taste)
Fill the shaker with ice
Shake vigorously for 15–20 seconds
Strain into a chilled martini glass or coupe
Garnish with 3 coffee beans (optional)