Add water, brown sugar and maple syrup to saucepan.
Bring to a boil and take off heat.
Once sugar is dissolved, then put it into a jar with a lid and cool in fridge.
Put large ice cube into whiskey glass.
Add bitters to glass.
Then add simple syrup and bourbon to glass and stir ingredients. Add sprig of rosemary and orange twist to garnish. Enjoy!
Brown sugar has molasses, which is why it is chosen for this simple syrup. It ends up making the simple syrup thicker and silkier.