Place the lemon, blackberries, and mint in a cocktail shaker or a glass jar with a lid. Smash the berries, lemon wedge, and mint leaves together until the berries resemble jam. The lemon and mint should also be aromatic.
On top of the muddled fruit and mint leaves, pour the bourbon, maple syrup, and ice cubes.Shake the blackberry bourbon smash together vigorously to mesh the ingredients.
Strain into a drinking glass or ice. Top with sparkling water or club soda. Garnish with additional fresh mint and blackberries and enjoy immediately.