Fill a cocktail shaker halfway with ice.
Add vodka, vermouth, St. Germain, cranberry simple syrup, lime juice, and cranberry bitters to the shaker.
Cover and shake vigorously until well chilled, about 15 to 20 seconds.
Strain into a chilled martini or coupe glass.
Garnish with fresh cranberries threaded onto a cocktail pick, accompanied by fanned-out mint leaves, or with a rosemary sprig studded with cranberries.
Serve immediately and enjoy!