TOMATOES: 3 medium, rip. Or 2 cups drained canned plum tomatoes.
Preheat the oven to 350 degrees. Cook the pasta according to package directions. Drain the pasta and set aside.
While the pasta is cooking, trim the zucchini but do not peel. Slice the zucchini thinly, place in a colander, and sprinkle with salt. Let stand at room temperature for 30 minutes to drain off excess moisture.
Put the zucchini between 2 layers of paper towels and squeeze dry with your hands. Place the zucchini in a well-greased 9 x 33 cm clear baking dish. Top with the onion slices, then with the potatoes. Dot with 2 tablespoons of the butter and sprinkle the prosciutto on top. Dot with 2 more tablespoons of butter. Sprinkle 0.75 cup Parmesan cheese on top.
In a separate bowl, mix the pasta, parsley, and basil with the salt and pepper to taste. Distribute the pasta over the vegetables in the baking dish. Dot with 2 more tablespoons of butter. Top the pasta with the tomatoes, dot with the remaining butter, and sprinkle the remaining Parmesan on top. The casserole can be refrigerated for 4 hours at this point.
Cover the baking dish with aluminum foil and bake 45 minutes to 1 hour. Turn off the oven, open the oven door, and let the dish stand for about 10 minutes before serving. [patH mcRecipe]