This cocktail from Gramercy Tavern is a take on a Boulevardier (which is like a Negroni, but with bourbon in stead of gin). Here, however, spicy rye is the star, complemented by the delicately bitter Sicilian amaro, Cynar.
'Boulevardier' on Serious Eats
This adaptation of the classic Boulevardier substitutes Gran Classico and homemade rhubarb syrup for the Campari. It's a luscious combination; bourbon and Gran Classico play very nicely together, and the fresh rhubarb adds just enough tart fruity flavor.
The Boulevardier takes the same Negroni formula--a good dose of gin brushed up with equal parts Campari and sweet vermouth--and gives it a twist by substituting whiskey for the gin.