Prep the zucchini by washing and slicing it lengthwise into thin strips, about 1/8 inch thick. Sprinkle salt over the strips and let them sit for 10-15 minutes to draw out moisture.
Heat a large skillet over medium heat, add olive oil, and cook the ground beef or turkey until browned. Drain excess fat and stir in marinara sauce. Simmer for 5 minutes.
In a bowl, mix together ricotta cheese, egg, salt, pepper, and Italian seasoning if desired.
Preheat the oven to 375°F (190°C). In a 9x13 baking dish, layer a small amount of meat sauce on the bottom, followed by zucchini strips, ricotta mixture, and a sprinkle of mozzarella. Repeat the layers, ending with meat sauce topped with remaining mozzarella and Parmesan.
Cover with aluminum foil and bake for 25 minutes. Remove foil and bake for another 15 minutes, until cheese is bubbly and golden.
Let cool for 10 minutes before slicing and serving.