Mix walnuts, marinara sauce (reserve ¾ cup for the pan), and sun-dried tomatoes.
Slice zucchini 1/16" lengthwise on a mandoline. Lay sliced zucchini on a cutting board that is covered with a kitchen towel or paper towels. Lightly sprinkle each slice with salt. Let sit for 15 minutes or until the zucchini starts to sweat, where water is drawn to the surface. Pat each zucchini slice off.
In an 7 ½" x 9 ½" pan, pour ¾ cup marinara sauce. Next, place zucchini noodles on marinara sauce, overlapping each slice. Spread ⅓ of tofu ricotta over zucchini noodles. Sprinkle nutritional yeast on top of tofu ricotta. Pour ½ of walnut sauce on top.
Layer more zucchini noodles, then ⅓ of tofu ricotta, nutritional yeast, and the rest of the walnut sauce. Finish with a layer of zucchini noodles, tofu ricotta, and nutritional yeast. Bake at 375°F for 35 minutes.
Notes
This zucchini lasagna will last 4-5 days in an airtight container in the fridge.