In a lasagna pan or 9 inch by 13 inch baking pan, ladle about 1 cup of the marinara sauce onto the bottom. This will keep the noodles from sticking.
Add one layer of noodles to cover the bottom. They can be slightly overlapping.
Top with another 1 cup of sauce and ½ of the roasted vegetables.
Add a second layer of noodles and another 1 cup of sauce. Top with 1 cup of the vegan cheese.
Add a third layer of noodles and spread out the spinach over the noodles.
Add a fourth layer of noodles, the remaining ½ of the vegetables and 1 cup of the vegan cheese.
Add the final layer of noodles, the remaining sauce and the remaining cheese.
You can top with some fresh basil leaves and sprinkle some nutritional yeast if you like. If you prefer the leaves to stay green, you can add them after baking!
Cover the lasagna and place in the oven for 30 minutes. Remove the cover and bake for another 20 to 30 minutes. The sauce should be bubbling and the cheese melted.
Let cool for about 20 minutes before serving so that it has time to set.