Heat 1 tablespoon of oil in a large skillet over medium heat. Season zucchini with salt and pepper. Cook zucchini in batches, for 8 to 10 minutes per batch. Transfer cooked zucchini from the pan to a dish and set aside.
Add butter and mushrooms to the skillet. Sprinkle with salt and pepper and cook until they soften and release their juices, about 4 minutes. Set aside.
In the same skillet, add another tablespoon of oil. Add the spinach and cook until wilted. Transfer to a paper-towel-lined plate. Squeeze out any excess moisture.
In a mixing bowl, combine ricotta cheese, Parmesan, egg, garlic, basil, parsley, and crushed pepper. Stir in spinach and season with salt and pepper.
Coat a 13” x 9” casserole dish, or large oven-safe skillet with cooking spray. Begin layers lasagna by spreading ½ cup of sauce on the bottom of the dish. Top with a layer of noodles, a layer of zucchini, a layer of mushrooms, ½ of the ricotta mixture and ½ cup of mozzarella. Spread 1/3 of the remaining sauce and repeat the layers. End with a layer of noodles, sauce and ½ cup of mozzarella.
Cover dish with foil and bake for 30 minutes. Uncover and bake for another 10 minutes, or until cheese is hot and bubbly. Allow to cool 15 minutes before serving.