Preheat the oven to 375°F.

Spray a 9x13-inch baking dish with nonstick cooking spray. Set aside.

Place the tofu, olive oil, lemon juice, nutritional yeast, salt, black pepper, garlic powder, and Italian seasoning in a large mixing bowl. Mash with your hands until it reaches the consistency of ricotta cheese. Adjust olive oil and seasonings to desired consistency and taste.

Transfer half of the tofu mixture to a food processor or blender. Process on high until very smooth, 2-3 minutes. Gently combine with the tofu in the mixing bowl.

To assemble the lasagna, spoon about a half cup of the marinara sauce into the baking dish to cover the bottom. Place 3-4 lasagna noodles in a single layer over the sauce. Drop 1/3 of the tofu mixture by spoonfuls over the noodles, and gently spread it into an even layer. Place 1/3 of the thawed and drained spinach over the tofu layer. Spoon 1/4 of the remaining marinara sauce on top. Repeat the layering process two more times. Place the last 3-4 lasagna noodles over the top of the dish, and cover with the last 1/4 of the marinara sauce.

Cover the baking dish with a sheet of aluminum foil.

Bake the lasagna on middle rack of oven for 50 minutes.

Remove the aluminum foil and continue baking until the dish is bubbling at the edges, about 10 minutes.

Check to see that lasagna is done. Remove from oven or add time as needed.

Remove the baking dish from the oven. Allow the lasagna to rest for 20 minutes before serving.