Preheat your oven to 375°F (190°C).
Slice the zucchini lengthwise into thin strips.
In a bowl, mix the ricotta cheese, salt, and pepper.
In a baking dish, spread a layer of marinara sauce.
Layer zucchini slices over the sauce.
Spread a layer of the ricotta mixture over the zucchini.
Sprinkle cooked ground beef over the ricotta mixture.
Repeat layers until all ingredients are used, ending with a layer of marinara sauce.
Top with shredded mozzarella and grated Parmesan cheese.
Bake in the preheated oven for 40 minutes, or until the cheese is bubbly and golden brown.
Let it cool for 10 minutes before serving.