Chill the glass. Put a coupe or martini glass in the freezer for 10 minutes, or fill it with ice water while you work.
Pull 1 shot of espresso. Use it within a minute or two, while the crema is still on top.
Fill a cocktail shaker about two-thirds full with ice.
Add the vodka, coffee liqueur, espresso and simple syrup, if using.
Seal the shaker and shake as hard as you can for 15 to 20 seconds. The outside of the shaker should feel frosty.
Empty the glass if you filled it with ice water. Strain the drink through the shaker's strainer and a fine mesh strainer into the glass.
Wait about 10 seconds for the foam to settle into a layer, then float 3 coffee beans on top.
