Rum Cake Fact Here are some facts about the Scrumptiousness . . . Rum cakes freeze beautifully for about 6 months. And it's as easy as 1,2,3 . . . 1. Wrap your rum cake in plastic, cling wrap, or wax paper for food. 2. Wrap in foil. 3. Place in the freezer where it will not be disturbed. Rum cakes can be slightly warmed in a microwave or at room temperature and served with (1) your favorite ice cream, (2) fruits of your choice, or (3) a beverage of your choice for an afternoon or late night snack.