1Heat oven to 350°F. Cook and drain pasta as directed on package. Rinse with cool water; drain.
2Meanwhile, in medium bowl, mix ricotta cheese, egg, Parmesan cheese, spinach and chicken.
3Spread 1 cup of the pasta sauce in bottom of 13x9-inch (3-quart) glass baking dish. Spoon about 2 tablespoons ricotta mixture into each pasta shell. Arrange shells, filled sides up, on sauce in baking dish. Spoon remaining sauce over stuffed shells.
4Cover dish with foil; bake 30 minutes. Sprinkle with Italian cheese blend. Bake uncovered 5 to 10 minutes longer or until cheese is melted.