To make the cranberry syrup: In a medium pot, bring 1/2 cup water, the maple syrup, and cranberries to a boil over high heat. Boil 5 minutes or until the cranberries begin to burst, then remove from the heat. Stir in the orange zest. Let cool. If desired, strain out the cranberries. This syrup makes enough for about 6 drinks.
In a cocktail shaker, combine 2-3 tablespoons cranberry syrup, the bourbon, lemon juice, cranberry juice, and orange bitters. Add ice and shake. Strain into a glass. Garnish with an orange slice and candied rosemary.