Preheat oven to 375F. Butter inside of shallow two quart baking dish. Combine first 6 ingredients in bowl and mix well. Place layer of zucchin1 in baking dish and layer with same of the cheese mixture. Repeat, ending with cheese mixture. Combine bread crumbs and Parmesan in small bowl.
Sprinkle over casserole. Dot with butter. Tent with foil and bake for 25 minutes. Remove foil and bake an additional 20 minutes until top is brown. Serve hot.