A helpful hit to keep in mind when making this recipe: While Irish whiskey is the standard alcohol of choice for this recipe, you can use brandy or other spirits in its place (or use up to 50% of the measure of a flavoured spirit like Calvados, Frangelico or Amaretto). You can also tailor the flavouring by adding ingredients like finely grated orange zest, extra cinnamon, mint leaves or peppermint extract or almond extract.