Preheat oven to 375°F (190°C).
In a large skillet over medium heat, sauté mushrooms, bell peppers, and garlic until softened; stir in spinach until wilted.
In a mixing bowl, combine blended cottage cheese, ricotta, egg, half of the parmesan, oregano, salt, and pepper.
Spread 1 cup of marinara sauce in the bottom of a 9x13 inch baking dish.
Layer lasagna sheets, followed by a portion of the cheese mixture, sautéed vegetables, zucchini slices, and marinara sauce.
Repeat layers until all ingredients are used, ending with a layer of lasagna sheets topped with remaining sauce.
Sprinkle the top with mozzarella and the remaining parmesan cheese.
Cover with foil and bake for 30 minutes.
Remove foil and bake for an additional 20 minutes until the cheese is golden and bubbling.
Let stand for 15 minutes before slicing to allow the protein structure to set.