Fill your shaker about a third of the way with ice.
Add all of the ingredients for the martinis to your shaker.
Cover and shake until well combined and chilled, about 10 to 20 seconds.
Squeeze a ribbon of chocolate syrup around the inside of your glasses.
Strain the martini mixture into your prepared glasses, dividing it evenly between the two glasses.
Garnish each with maraschino cherries. Enjoy immediately.