Prepare the Vegan Bolognese Sauce. You'll need 3 to 4 cups for layering in the lasagna (depending on how saucy you like it). Measure out that amount and reserve the remainder for serving the baked lasagna. While the sauce simmers, preheat the oven to 350F. Lightly grease an 8" x 11" baking dish with olive oil. Prepare the Cashew Mozzarella Sauce (recipe below) and Vegan Parmesan Cheese (if using).
Spread about one-quarter (i.e., ¾ to 1 cup, depending on how saucy you prefer your lasagna) of the bolognese into the bottom of the prepared baking dish. Add a layer of lasagna noodles (I like to use any broken bits in the box to fill in the gaps at the edges of the pan/dish). Cover the noodles with about half of the mozzarella sauce. Top with another ¾ to 1 cup of the bolognese.
Add another layer of lasagna noodles. Top with another ¾ to 1 cup of the bolognese.
Finally, add the last layer of lasagna noodles and cover with the remaining bolognese, and top with the remaining mozzarella sauce.
Cover the lasagna with foil and bake for 30 minutes. Then, remove the foil and sprinkle with as much of the vegan parmesan (if using) as desired and continue to bake for another 20 minutes.
Remove the lasagna from the oven and let rest for at least 5 minutes before serving.
Sprinkle with chopped parsley (if using) for a pop of color and herbaceous freshness.
Leftovers can be refrigerated for up to 5 days or frozen for up to 1 month.