In a skillet, brown the ground beef or turkey. Drain any excess fat and add the marinara sauce. Let it simmer for about 5 minutes.

In a bowl, combine the ricotta cheese, egg, Parmesan cheese, salt, pepper, and Italian seasoning. Mix well until smooth.

In a baking dish, start by spreading a layer of meat sauce on the bottom.

Then add a layer of noodles, followed by the ricotta mixture, some zucchini slices, and a sprinkle of mozzarella cheese.

Repeat these layers until all ingredients are used, finishing with a layer of mozzarella on top.

Cover the baking dish with foil and place it in a preheated oven at 375°F (190°C).

Bake for 30 minutes. After that, remove the foil and bake for another 10-15 minutes, or until the cheese is golden and bubbly.

Once out of the oven, let the lasagna sit for about 10 minutes before slicing. This helps it hold its shape for serving.