Crumble the tofu into a large bowl until it resembles the texture of ricotta cheese. Add the spinach, nutritional yeast, garlic powder, basil, and salt. Stir to combine and set aside.
Lasagna
Preheat oven to 400 degrees. Boil the noodles until soft. Or, if using noodles that will cook in the oven, move to step 2.
Saute onion and garlic on medium high heat for 3 minutes in a large nonstick pan with 1/4 cup water.
Add the mushrooms and broccoli and cook until the onions are limp and the mushrooms give up their liquid and the broccoli is crisp-tender. Add the herbs and spices. Stir to combine and reserve.
Steam the sweet potatoes until soft. Mash in the same pan as you steam them and reserve.
Assembling
Cover the bottom of a 9 x 13″ casserole dish with a layer of pasta sauce. Add a layer of noodles. Cover the noodles with sauce again.
Spread 1/2 of the vegetable mixture over the sauced noodles and cover with a layer of tofu ricotta and more sauce.
Add another layer of noodles. Top with sauce, the other half of the vegetable mixture, a layer of mashed sweet potato and top with sauce.
Top with the final layer of noodles, more sauce, and the thinly sliced tomatoes.
Cover with foil and bake in the oven for 45 minutes. Remove the foil, sprinkle with the cashews, and return to the oven for 15 minutes. Let sit for 15 minutes before serving.