The Frankfurt Old Fashioned is a twist on the classic Old Fashioned cocktail, with a Frankfurt twist. It combines bourbon whiskey, a sugar cube, Angostura bitters, and a splash of apple liqueur. The cocktail is muddled with the sugar cube and bitters, then stirred with ice and strained into a rocks glass. It is garnished with an orange twist. The Frankfurt Old Fashioned is a rich and flavorful cocktail that combines the warmth of bourbon with the subtle sweetness of apple liqueur.