Carefully hold one end of cinnamon stick over a flame for a few seconds until you see it start to turn black and emit smoke.
Place cinnamon stick on a dish then quickly place rocks glass upside down on top of it to trap the smoke.
Meanwhile, add cinnamon simple syrup and bitters to mixing glass and stir.
Fill halfway with ice then pour in bourbon and stir until chilled to touch.
Remove cinnamon stick from rocks glass then add a large ice cube and strain in the cocktail liquid.
Cut off a strip of orange peel then squeeze it over top of cocktail to express oil. Drop peel into glass along with charred cinnamon stick and serve.
Notes
To Make the Cinnamon Syrup
Add one cinnamon stick (or two teaspoons ground cinnamon), 1 ½ cup brown sugar, and one cup water to a small saucepan over medium heat and stir until dissolved.
Bring the mixture to a boil then remove it from heat and steep until cooled.
Strain out any solid pieces and transfer the cooled syrup to a container to store. Makes 18 servings.
PreparationTo large batch four a crowd, combine two ounces of cinnamon simple syrup with 8-12 dashes of bitters. Add the ice and six ounces of bourbon then stir until chilled. Divide the liquid between four smoked rocks glasses over ice and express orange oil over each. Makes four servings.