2
Mix egg, ricotta and Parmesan in medium bowl until blended. Stir in 1 cup mozzarella.
3
Reserve 9 pepperoni slices, and 2 Tbsp. each peppers and onions. Quarter remaining pepperoni slices; place in separate medium bowl. Add pasta sauce, water, remaining peppers and onions; mix well.
4
Spread 1/2 cup sauce onto bottom of 8-inch square baking dish sprayed with cooking spray. Top with layers of 2 lasagna noodles, broken to fit; 1/3 of the ricotta mixture; and 1/2 cup of the remaining sauce. Repeat layers twice. Top with remaining noodles, sauce, mozzarella, and reserved pepperoni, peppers and onions. Cover with foil sprayed with cooking spray.
5
Bake 45 min. or until heated through, uncovering for the last 10 min. Let stand 10 min. before cutting to serve.