This cocktail was developed by mixologist Lynn House at Chicago's Blackbird restaurant. She explains: "The Oz is named after a jazz club that used to be here in Chicago. It was in my neighborhood and they were known not only for amazing music, but for their cognac and champagne selection. It was a favorite hang out of mine — and it was also the first place to serve Pierre Ferrand cognacs in the United States. When I met Pierre Ferrand's president Alexandre Gabriel this summer, he told me the story of his cognacs and mentioned the bar Oz. I lit up because I knew the place well, and I told him my next cognac cocktail would be called Oz in honor of our shared bond."