Add large ice cube to a rocks glass.

Add simple syrup, rye whiskey and bitters to the glass.

Stir briefly.

Take a piece of orange peel and bend it between two fingers over the cocktail glass, with the outside peel facing the cocktail glass. As you bend the orange peel, bring a lit lighter to the bent exterior of the orange peel and briefly ignite the orange peel. Note that you are igniting the little juice from the peel that comes out, and not the piece of peel itself. The peel should not light on fire.

Rub the peel around the rim of the glass and drop into the cocktail. Serve immediately.