Ice 3 ounces vodka 1 ounce passion fruit juice 1 ounce simple syrup (equal parts sugar and water heated until the sugar dissolves, then chilled) 1/2 teaspoon freshly squeezed lime juice Passion fruit seeds (optional, for garnish)
Fill a cocktail shaker with ice. Pour the vodka, passion fruit juice, syrup, and lime juice into the shaker. Cover and shake vigorously, until combined and chilled, about 30 seconds. (In general, by the time the shaker mists up the drink is ready.) Strain cosmo into a chilled cocktail glass. Sprinkle with passion fruit seeds, if desired.