To adhere to the original recipe, you should smash a sugar cube and then painstakingly stir this with bitters into a paste. Life is just too short to faff...
Made with Laird's Bottled-in-Bond & Wild Turkey 101 Rye. Pretty tasty as-is. Apple is balanced. Whiskey is smoothed out. Subtle orange. and brown sugar. Not too sweet for me.
I've tried this about a half dozen times now. Like y'all have suggested, reducing the sugar - in my case, to 5 ml - has resulted in a more harmonious drink. This in addition to skewing the spirit specs to 6:5, in favor of Old Forester 100-proof rye, which somehow has been a stalwart ingredient.
Made with half the Demerara and it works! Orange forward and refreshing. We had to use apple brandy as applejack is not available in Canada. Nice drink!