Preheat the oven to 350F.
Start by making the vegan parmesan. In a food processor or blender, add the cashews, garlic, nutritional yeast and salt. Pulse a few times until you get a fine crumb. Set aside.
Prepare the tofu ricotta. Set aside. Cook the noodles according to the package's instructions, until al dente.
Assemble the lasagna: Spread 1 scant cup of marinara sauce at the bottom of a 8" x 11" (2L) casserole dish. Add 1 layer of lasagna noodles (I used 3 noodles per layer). Next, spread half of the vegan ricotta. It doesn't have to be perfectly spread. Top with 1 small handful of spinach. Add a second layer of lasagna noodles, then spread 1 scant cup of marinara sauce. Add a third layer of lasagna noodles, followed by the other half of the ricotta. Add another small handful of spinach. Finally, add one last layer of lasagna noodles and top it with the remaining marinara sauce.
Sprinkle with a generous amount of vegan parmesan on top. If you have leftover vegan parmesan, store it in the fridge in an airtight container and use it in salads, casseroles, pasta, etc.
Cover the lasagna with aluminum foil and bake for 30 minutes at 350F.
Remove from the oven and let it cool for 5-10 minutes before serving.