If you don't have any homemade candied peel (mixed peel) subtitute in some apricots or dried oranges,
Apple Brandy is also known as Calvados. It is a strong brandy from France. Other brandys can be used, including Grand Marnier which is an ornge brandy. Bourbon or rum will also work. If you want a non-alcoholic fruitcake make a simple syrup of one part sugar to one part water, boiled briefly with a drop or two of a flavored extract for thje soaking liquid.
I used hard cider. Regualr cider or apple juice will work as well