* Shredded and divided Cook Lasagna noodles according to package directions, omitting salt, and then drain. Cook sausage until browned, Stirring to crumble; drain. Stir spaghetti sauce into sausage, and set aside. Combine egg and next five ingredients, stirring well. Spread about 1/2 cup meat sauce in a lightly greased 13x9x2" baking dish. Layer half of the noodles, half of ricotta cheese mixture, one-third of mozzarella cheese, and one-third of remaining meat sauce; repeat layers using equal amounts. Arrange mushrooms and pepperoni slices on top. Bake at 375 ° for 20 mins. Sprinkle with remaining cheese, and bake an additional five mins.