1 ounce Grand Marnier centenaire: Zovkic uses this orange-flavored cognac, which is aged for 15 to 20 years, instead of the typical Cointreau. "It stays with you a long time after a sip," he says. The substitution is a nod to the sidecar's history, a version that credits the Hotel Ritz in Paris with its creation after World War I. Louis-Alexandre Marnier-Lapostolle, the founder of Grand Marnier, was also a backer for the Ritz, he says.