I have an old Scandanavian cookbook,(CIA, Chicago, 1965) from my husband's grandmother, which has a recipe for an apple cake that calls for 16 (about 7 ounces) rusks, which are crushed and made into what sounds very much like a graham cracker crust, and then layered with applesauce and butter in a baking dish, chilled several hours, and topped with 1/4 cup sifted confectioner's sugar and a vanilla suace. I'd like to try this recipe, but have never actually heard of or seen rusks. I googled them and they look like some type of hard cracker...can anybody give me any more info, such as where I could find them, or what might be an acceptable substitute for them in this apple cake? Would something like graham crackers, or maybe gingersnaps work? Would love to hear from authentic Scandinavian (Swedish) cooks!