Based on the Brandy and Blackberry Lavender Shrub.
Pre-make the blackberry shrub (takes about a week).
Hand-slap a rosemary sprig and add to a shaker.
Add ice to the shaker.
Add 0.25oz simple syrup.
Add 0.5oz lemon juice.
Add 0.5oz dry vermouth.
Add 2oz blackberry shrub.
Add 2oz brandy.
Shake, then strain into a cocktail glass.
Optionally garnish with a lemon twist and rosemary sprig.