Combine the espresso, Vanilla Bean Simple Syrup and bourbon in a cocktail shaker with a few ice cubes. Shake for 10 seconds. Put the ice cubes in a tall glass, pour over the espresso mixture and top with warm, frothy milk. Dust with cinnamon if desired and serve.
Vanilla Bean Simple Syrup:
Combine the sugar and 1/2 cup water in a small saucepan. Bring to a boil over high heat and cook until sugar has melted, about 3 minutes. Add the vanilla bean and seeds. Let cool to room temperature, then remove the vanilla bean. Transfer the syrup to a bowl, cover and chill until cold.