Layered Rigatoni Bake

Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Cook and drain pasta as directed on package except omit salt; keep warm.

Spray 3-quart saucepan with cooking spray; heat over medium heat. Add onions to saucepan; cook and stir 1 minute. Add butter and flour; cook 2 minutes, stirring constantly, until mixture is smooth and bubbly; remove from heat. Gradually stir in milk with wire whisk. Heat to boiling, stirring constantly; boil and stir 1 minute. Remove from heat; stir in ricotta cheese and spinach.

In separate 3-quart heavy saucepan, heat oil over medium heat; add tomatoes to oil, crushing tomatoes with spoon. Stir in basil, salt and pepper; cook uncovered about 10 minutes, stirring occasionally, until mixture begins to simmer and basil wilts. Remove from heat; discard basil.

Over bottom of baking dish, spread half of the tomato sauce (1 1/4 cups). Arrange half of the pasta, 7 rows lengthwise by 9 or 10 rows widthwise, over tomato sauce. Spread half of the ricotta mixture (2 cups) over pasta. Repeat layers, ending with ricotta mixture. Sprinkle with bread crumbs and Parmesan cheese.

Bake uncovered 30 minutes or until hot and bubbly. Let stand 15 minutes before serving.