For an extra layer of flavor, try using a combination of different types of bread, such as challah or brioche, along with the cinnamon raisin bread. Feel free to adjust the amount of rum to your liking, or substitute with rum extract for a non-alcoholic version. If you don't have apples, you can use other fruits like pears or peaches. The rum sauce can be made ahead of time and stored in the refrigerator until ready to use. Simply reheat it gently before serving.