Preheat oven to 375º. Bring a large pot of water to boiling and boil lasagna noodles about 8 minutes or until tender.
While noodles are cooking, place tofu, 2 tablespoons of nutritional yeast, dried basil, dried oregano, garlic powder, dried minced onion, salt, & pepper in a food processor and blend until smooth. Or you can mash & blend in a bowl with a fork if you don't have a food processor (it just won't be as smooth and creamy).
When noodles are done, drain and lay flat in a large baking dish full of cold water. This will keep them from sticking to each other and cool them off so you don't burn your fingers.
Slice the zucchini into 1/4 inch thin slices.
In a 9 X 13 baking dish from the bottom up: layer 1 cup of marinara, 5 noodles, 1 cup marinara, 2 cups spinach, 5 noodles, tofu mixture, 1 cup marinara, 5 noodles, 1 cup marinara, 2 cups baby spinach, 5 noodles, 1 cup marinara, thinly sliced zucchini and then sprinkle with 2 tablespoons of nutritional yeast.
Cover with foil and bake for 30 minutes. Remove foil and bake for another 10-15 minutes or until zucchini is lightly browned.