Heat oven to 375° . In large skillet, cook meat and onion until meat browns, drain. Stir in spaghetti sauce, heat to boiling. Reduce heat to low, simmer 5 minutes. Meanwhile, cook pasta according to package directions for 7 minutes, drain. In large bowl, stir together ricotta cheese, egg, parsley, pepper and salt. In 13x9x2 inch baking dish, spread 1 cup meat sauce, evenly layer one-half pasta over sauce. Spread ricotta mixture over pasta, sprinkle with 1 cup mozzarella cheese. Repeat layers of meat sauce and pasta. Spread remaining meat sauce over pasta, cover pasta completely, sprinkle with remaining mozzarella cheese. Sprinkle with Parmesan cheese, if desired, cover with foil. Bake 30 minutes. Remove foil, bake 5 minutes or until hot and bubbly. 10 servings (1 cup each)
I make 1/2 recipe and place in 9x5x3 baking dish.