This classic cocktail was likely invented at Harry's New York Bar in Paris, circa 1931.
3 oz. cognac
1 oz. Cointreau (or triple sec)
2 lemon slices
1. Juice lemon, reserving rinds. Rub rims of two stemmed cocktail glasses with pulp side of lemon rind, then dip moistened rims into a saucer of sugar.
2. Fill a cocktail shaker with ice, add reserved lemon juice, cognac, and Cointreau; shake well. Strain into sugar-rimmed glasses and garnish each with a slice of lemon.