Preheat oven to 375°. (Note: After removing the zucchini noodles from the oven, increase the temperature to 400°.)

1. Place sliced zucchini on large baking sheet coated with non-stick cooking spray. Sprinkle with salt and roast in the oven for 15-20 minutes to help dry out the zucchini a bit.
2. While the zucchini is roasting, in a medium bowl make the ricotta mixture by whisking together the ricotta, eggs, salt and pepper. Add the spinach and stir to combine.
3. In a separate bowl, make the shredded cheese mixture by combining the mozzarella, parmesan, basil, and oregano.
4. Make your mixed vegetable filling by heating a large skillet over medium-high heat and adding the olive oil. Add the garlic and onions and cook, stirring, 1 minute. Add the carrots and yellow squash. Cook until the vegetables are tender, 3 to 5 minutes. Season with salt and pepper. Remove from the heat and drain off any excess liquid.
5. If you didn’t already, increase the oven temperature to 400 degrees F.
6. Assemble the lasagna in a 9 by 13-inch glass baking dish with the following layers: Spread a third of the marinara sauce over the bottom of the baking dish. Arrange a layer of zucchini noodles on top. Spread a third of the ricotta mixture over the zucchini noodles. Spread a third of the cooked mixed vegetables. Sprinkle with a third of the shredded cheese mixture. Repeat to make two more layers, ending with the shredded cheese mixture on top.
7. Cover with foil and bake 30 minutes.
8. Remove the foil and continue to bake until the top is golden brown, about 10-15 minutes more.

Let cool at least 10 minutes before serving.