From a recipe by Damon Boelte of Grand Army bar and restaurant
I used Calvados but feel free to use another apple brandy or Applejack. The original recipe calls for
Fee Brothers Whiskey barrel-aged bitters, but I found a tiny dash of apple,
apple blosson, or aromatic bitters (such as Angostura) is nice. Although another complimentary-flavored bitters would work. Sparkling (hard) cider could also be used in place of the sparkling wine or Champagne.
Elderflower liqueur is sold under several brand names, including
Vedrenne and
St. Germain.