Cook Rigatoni until almost tender - set aside. In a saucepan, bring a small amount of water to boil. Add zucchini and cook until crisp and tender. In a buttered baking dish layer a third of the Rigatoni, sauce, cheese and zucchini. Continue until you have three layers of each. Top with some shredded cheese. Sprinkle olive oil on top. Bake 30 minutes until cheese is melted at 350 degrees.
Serves 4-6.