Makes 4 drinks

To a large cocktail shaker, add bourbon, lemon juice, blackberry simple syrup (recipe follows), tonic water or sparkling wine (optional), and a handful of ice; shake to combine. Pour into ice-filled glasses. Garnish with rosemary sprigs if desired.

To a saucepan over medium heat, add the blackberries, sugar, and water and bring to a simmer. Cook for 15 to 20 minutes, stirring occasionally, until blackberries have softened and syrup thickens. Strain the syrup through a fine mesh sieve. Let cool for 20 minutes before using.