Preheat oven to 375 degrees Fahrenheit.
Lightly salt the sliced zucchini and let sit for 10 minutes. Pat away extra moisture.
Beat together the ricotta, basil, 1/2 cup parmesan cheese, egg, salt, and pepper. Set aside.
In a 9x12 inch casserole dish, spread out about a 3/4 cup of the tomato sauce on the bottom of the dish.
Spread out a layer of sliced zucchini over the tomato sauce.
Spread out 3/4 to 1 cup of the ricotta cheese mixture over the zucchini.
Sprinkle with 1 cup of the shredded mozzarella cheese
Repeat the sauce, zucchini, ricotta cheese, and mozzarella layers. Cover with foil and bake for 30 minutes.
Take the foil off and bake for 20 minutes.
Top with the rest of the parmesan cheese (1/2 cup) or however much you want and bake for another 10 minutes. Let the lasagna sit for 10 minutes before serving.