This is one of the most-requested drinks at Jimmy's Bronx Cafe in New York City. The recipe was shared with us by the restaurant's owner, Jimmy Rodriguez.
In a cocktail shaker, combine vodka, schnapps, lemon juice, simple syrup, 1/2 cup water, and 1/2 cup ice cubes. Place top on shaker, and shake until combined and well chilled. Fill a tall tumbler with ice cubes. Add blueberries. Strain vodka mixture into glass. Garnish glass with lemon slice. Serve immediately.