Preheat your oven to 375 degrees F (190 degrees C).
Cook ziti pasta according to package directions. Drain and set aside.
In a large skillet, brown the ground beef over medium heat. Drain off any excess grease.
Stir in the marinara sauce and bring to a simmer. Cook for 5 minutes.
In a medium bowl, combine ricotta cheese, egg, Parmesan cheese, salt, and pepper. Mix well.
In a greased 9x13 inch baking dish, layer half of the cooked ziti. Top with half of the ricotta mixture, then half of the meat sauce.
Repeat the layers: remaining ziti, ricotta mixture, and meat sauce.
Sprinkle the shredded mozzarella cheese evenly over the top.
Bake for 25-30 minutes, or until the cheese is melted and bubbly and the edges are golden brown.
Let stand for 5-10 minutes before serving.
Notes
For an extra layer of flavor, you can add some chopped fresh parsley or basil to the ricotta mixture. If you prefer a spicier kick, add a pinch of red pepper flakes to the meat sauce.