Spread 1/2 cup pasta sauce onto bottom of 8-inch square foil pan sprayed with cooking spray. Cover with layers of 1/3 of the zucchini, half the ricotta mixture and 1/2 cup sauce. Repeat layers. Top with remaining zucchini, sauce, shredded cheese and Parmesan; cover with foil. Cut small slit in foil to allow steam to escape.