Add all the ingredients into a shaker with ice and shake.
Strain into a chilled coupe glass.
Garnish with an apple slice.
*Cinnamon syrup: Add 1/2 oz cinnamon bark, 2 cups turbinado sugar and 2 cups water into a saucepan and bring to a boil, stirring until sugar dissolves. Cover saucepan and let simmer for 2 minutes. Remove from heat and let sit, covered, for at least 24 hours. Strain into a container. Keeps in a refrigerator for 2 weeks.