Cook penne to desired doneness as directed on package. Drain.
Meanwhile, heat oven to 400°F. Spray 8-inch square (2-quart) baking dish with nonstick cooking spray. In medium saucepan, heat spaghetti sauce over low heat.
In large bowl, combine cooked penne, spinach, cottage cheese, Parmesan cheese and salt; mix well. Add beans; toss gently to mix.
Spoon 1/2 the mixture into sprayed dish. Spread with 1 cup warm spaghetti sauce. Top with remaining penne mixture and remaining sauce. Sprinkle with mozzarella cheese.
Bake at 400°F. for 20 minutes or until thoroughly heated.