Make sugar syrup by combining Demerara/Turbinado sugar and water in a saucepan and bringing to a boil stirring continuously until sugar dissolves. Cool and bottle.
Measure all ingredients into a cocktail shaker.
Add 5-6 ice cubes. Shake vigorously and strain into a short glass.
Add 1-2 ice cubes to the glass and garnish with a lemon wedge and a rosemary sprig.