Cook Lentils: Boil 1 cup of red lentils in 3 cups water for 20 minutes, then drain. Stir in marinara sauce and set aside.
Make Ricotta: Blend cashews, tofu, nutritional yeast, lemon juice, salt, basil, oregano, and garlic powder in a food processor until smooth.
Assemble Lasagna: Spread 1 cup lentil marinara at the bottom of a 9x13 inch casserole dish. Layer with noodles, ricotta, spinach, and marinara. Repeat layers.
Bake: Cover with foil and bake at 350°F for 40 minutes.
Add Mozzarella: After 40 minutes, top with vegan mozzarella and bake uncovered for 20 more minutes.
Let cool for 15 minutes before serving. Enjoy!