Slice zucchini. Preheat the oven to 400°F (200°C). Slice the zucchini lengthwise into thin slices, as thin or thick as you'd like. Set aside.
Make bolognese. Add the ground beef to a large pan over medium-high heat. Finely break down the ground beef with a spatula and pan-fry until browned and no longer pink. Then, pour the pasta sauce on top (remember to reserve 1/2 cup) and stir together, then remove from heat.
Make ricotta mix. In a medium bowl, make the ricotta mix by stirring together the ricotta cheese, parmesan, egg, salt and pepper.
Add the first layers. Spread 1/2 cup of pasta sauce onto the bottom of your 9x13-inch casserole dish. Then add your zucchini slices on top of the pasta sauce. They can overlap or you can place them side-by-side.
Add the secondary layers. Top the zucchini with 1/2 of the bolognese sauce, and evenly spread 1/2 the ricotta mix on top of that. Then, add 1/2 cup of grated mozzarella with a sprinkle of chopped parsley and basil.
Repeat these layers one more time.
Finish the topping. Top the lasagna with a final layer of zucchini slices, a sprinkle of chopped parsley and basil, and 1/2 cup of mozzarella cheese.
Bake. Place the lasagna in the oven and cook for 40 to 45 minutes. Broil for a couple of minutes to get a nice golden top. Garnish with whole basil leaves and serve.