Place about 6-8 blueberries and the simple syrup in a cocktail shaker. Muddle gently until the blueberries break down.

Add the vodka, triple sec, and fresh lemon juice to the shaker. Fill with ice and shake well.

Double strain into a chilled martini glass to remove any solids.

Add a splash of cranberry juice for extra color (if using) and garnish with a few extra fresh blueberries on top.