Beat the egg in a bowl. Add the entire container of ricotta cheese, ½ teaspoon of salt, ¼ teaspoon of pepper and 1-2 teaspoons of chopped parsley. Mix well. Cover and refrigerate the ricotta mixture until your ready to assemble the baked ziti.
Brown the ground beef, drain well and return to the pot.
Pour the sauce into the pot with the cooked ground beef and heat. If you'd like to add a little extra seasoning or parmesan cheese as I sometimes do add it now while you are heating the sauce.
Cook the ziti noodles per the box instructions. While the pasta is cooking grate the block of cheese. When the pasta is cooked el dente drain it well and pour into a large baking pan.
Add the meat and sauce to the pasta and stir. Add ⅔ of the pre-shredded mozzarella cheese and stir well. Add ⅓ of the ricotta cheese mixture. Mix well.
Randomly sprinkle the two different types of shredded mozzarella cheese over the top of the ziti covering as much of the ziti noodles as possible.
Loosely cover your tray with aluminum foil being sure to tent it over the center of the tray so the melting cheese doesn't stick.
Bake it in a 375 degrees over for 30-45 minutes or until it is bubbling and the cheese is melted.
Some people like to spread an even layer of ricotta cheese over the ziti. If you do then feel free to spread the ricotta cheese over the top instead of adding the spoonfuls as I do. My mom did it this way and I have always done it this way. I do the same when I make lasagna.