Mix walnuts, marinara sauce (reserve ¾ cup for the pan), and sun-dried tomatoes.
Slice zucchini 1/16" lengthwise on a mandoline.
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.