Heat oven to 375°F. Cook and drain pasta as directed on box.
Meanwhile, spray 12x8-inch (2-quart) glass baking dish with cooking spray. In 12-inch nonstick skillet, cook beef, onion and garlic over medium heat, stirring frequently, until thoroughly cooked.
Stir zucchini into ground beef. Cook 2 minutes. Stir in tomato sauce, tomatoes, oregano, salt and pepper. Heat to boiling. Add drained pasta; toss to coat. Spread in baking dish.
Cover dish tightly with foil; bake 20 minutes. Remove foil; sprinkle with cheese. Bake uncovered about 5 minutes longer or until cheese is melted.