In a large bowl, combine the ricotta, mozzarella, and egg - add salt and pepper, to taste.
Cook the pasta according to the package directions for AL DENTE. You don't want them to be cooked all the way - they will finish cooking in the oven. Drain and rinse under cool water to stop the cooking process. Add the pasta to the bowl with the cheese mixture.
In a large skillet, brown the ground beef and when it's just about done add the onion and garlic. Cook until the onion is soft and the meat is cooked through. Drain any grease but do not rinse.
Add the spaghetti sauce, tomatoes, and seasonings to the meat in the skillet. Simmer for 30 minutes, then remove 3½ cups of sauce - let it cool. Once cooled, add the reserved sauce to the pasta-cheese mixture and combine.
In the baking dish, layer half of the pasta, then HALF of the remaining sauce, and HALF of the mozzarella.
Repeat another layer of pasta, sauce and the rest of the cheese.
Bake in the preheated oven for 20 - 30 minutes or until bubbly and the cheese is melted and golden brown. Remove from oven and let it sit for a few minutes before serving.