Preheat oven to 375°F (190°C) and grease a 9x13 inch baking dish.
In a heat-proof bowl, combine TVP and boiling water; let sit for 10 minutes until hydrated.
Sauté onion, bell peppers, zucchini, and garlic in a non-stick pan until softened, approximately 6-8 minutes.
Stir the hydrated TVP and marinara sauce into the vegetable mixture; simmer for 5 minutes.
In a separate bowl, combine cottage cheese, beaten egg, spinach, and 1/4 cup of Parmesan cheese.
Spread 1 cup of the meatless sauce on the bottom of the prepared baking dish.
Layer three lasagna noodles over the sauce, followed by 1/3 of the cheese mixture and 1/4 of the remaining sauce.
Repeat the layers twice more, finishing with a final layer of noodles and the remaining sauce.
Top with mozzarella and the remaining Parmesan cheese.
Cover with foil and bake for 25 minutes. Remove foil and bake for an additional 20-25 minutes until cheese is golden and bubbly.
Let rest for 15 minutes before slicing to ensure layers set.