Add the rye whiskey, dry vermouth, maraschino liqueur and Angostura Bitters to the glass.
Stir until chilled and well blended (about 20 seconds).
Strain into a chilled cocktail glass.
Garnish with an orange twist or cherry, if desired
Notes
Amer Picon, a French bitter orange liqueur that can be challenging to find. You can substitute a different bitter orange liqueur or a combination of bitters and orange liqueur.