Moderated this to reflect the Savoy Cocktail Book, replacing applejack (which is GNS + apple brandy) with the correct ingredient, apple brandy or Calvados.
I've always felt that this drink cries out for bitters or anything to give it some depth. Luckily, when I was served this at a bar as a bartender's choice, it was served with great enthusiasm which gave it some dimension to add to the flabby build.