Smooth and bold, cold brew coffee is the perfect mixer for this coffee cocktail. Cold Brew Martini Recipe: Place two martini glasses in the freezer to chill for up to one hour. Put one espresso bean in the bottom of each glass. Pour 2 oz cold brew (we used used Starbucks® Cold Brew Coffee Pitcher Packs), 4 oz vanilla-flavored vodka and 2 oz coffee-flavored liqueur into a shaker filled with ice. Shake vigorously. Strain into the chilled martini glasses, serve and enjoy.