1Place a cocktail or Old Fashioned glass in the freezer to chill.
2Combine the whiskey, Campari, and sweet vermouth in a cocktail shaker and fill it halfway with ice. Stir until the outside of the shaker is frosted, about 30 seconds. If you’re using an Old Fashioned glass, add ice cubes to it. Strain the drink into the chilled cocktail or Old Fashioned glass. Garnish with the orange twist and serve.