STIR powdered sugar with lemon juice in base of shaker until sugar dissolves. Add gin, SHAKE with ice and fine strain into chilled. TOP with champagne and lightly stir. (Consider pouring half the champagne into the glass first to help reduce foaming.)
The use of powdered sugar instead of sugar syrup adds an attractive sherbet note to this cocktail. However, the drink also works well with sugar syrup – use ¼oz/7.5ml sugar syrup in place of the 1½ spoons of powdered sugar.
Prior to the 1980s/90s, the French 75 cocktail was a long drink, served in an ice-filled Collins glass. This modern flute serve has become the usual serve with the Collins version now all but forgotten.