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 beef is thoroughly cooked.

Stir zucchini into beef mixture; 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.

High Altitude (3500-6500 ft): Increase covered bake time to 30 minutes.