In a cocktail shaker or glass jar, add blackberries, rosemary, lemon juice and honey. Muddle all of the ingredients together, squishing everything to release the juices. Add the tequila and orange bitters.
Add ice to your glass and strain the drink over the ice. Top the glass with a little more ice, pour the sparkling water over, and gently stir to combine. Garnish with fresh rosemary and blackberries.