Place a coupe or martini glass in the freezer. Combine the 2 oz vodka, 1 oz Kahlúa, 1 oz cold brew concentrate, and 0.5 oz simple syrup in a cocktail shaker and fill two-thirds with ice.

Seal the shaker and shake hard for at least 15 seconds until the outside feels very cold and frosty.

Strain into the chilled glass in one steady pour, then place 3 coffee beans in the center of the foam and serve immediately.