This signature cocktail from The Vault at Pfaff's in New York City finds harmony in an unusual combination: blended scotch and genever. Tart, easy-drinking, and just a little frothy from the use of egg white, it's one of those drinks you're not going to want to put down.
Add all of the ingredients, except for the bitters and garnish, to an iced cocktail shaker. Shake vigorously and strain into a martini glass. Add a dash of bitters and garnish with an orange twist.