Preheat the oven to 375°F (190°C).
In a large skillet over medium heat, cook the ground beef until browned. Add the minced garlic and cook for another minute. Drain any excess fat.
Stir in the marinara sauce, dried oregano, and dried basil. Simmer for about 5 minutes.
In a medium bowl, mix the ricotta cheese, beaten egg, and 1/4 cup of grated Parmesan cheese.
Spread a thin layer of the meat sauce in the bottom of a 9x13-inch baking dish.
Place a layer of zucchini slices over the sauce, then spread a layer of the ricotta cheese mixture on top of the zucchini. Sprinkle with a little salt and pepper.
Repeat these layers ending with a layer of meat sauce, and then sprinkle the remaining mozzarella and Parmesan cheeses on top.
Cover the dish with aluminum foil and bake for 30 minutes. Remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and golden brown.
Let stand for 10 minutes before slicing. Serve and enjoy!