I developed this recipe it's a great casserole, since I really don't bother to measure for this recipe, the exact amounts are not really required! The olives are only optional, I like to add them in, it brings out so much extra flavor! Of coarse you can make this recipe using your own favorite pasta sauce if desired! This can be made using all ground beef if desired. I strongly suggest to make the tomato/beef sauce a day or up to 2 days in advance and refrigerate to blend the flavors! For a smaller casserole reduce the spagetti amount and bake in a 13 x 9-inch baking dish, just make certain to cook enough spaghetti for two layers, use as much pasta as you want, a little or a lot! If you have any leftover sauce you can freeze it for the next time! Prep time does not include making the meat sauce.