Boil simple syrup and rosemary in a small saucepan, and allow it to cool to room temperature.
Strain the syrup and add it to a shaker with bourbon, lemon juice, and marmalade. Add ice and shake.
Pour into a glass with ice. Add maple syrup, orange juice, and egg white to the shaker. Shake until frothy and pour over cocktail. Garnish with a sprig of rosemary.