Add the oil to a large frying pan and bring heat to medium. Drop in the onion and garlic and cook for 5 minutes. Now add the zucchini, mushrooms, 1 teaspoon salt, ½ teaspoon garlic granules, and ½ teaspoon Italian seasoning. Saute for 8 minutes stirring frequently. Add the water 1 tablespoon at a time if the pan is getting dry. Now add the roasted red peppers, sun-dried tomatoes, and spinach. Reduce heat to simmer, cover pan, and cook for 5 minutes or until the spinach is completely wilted.
While the vegetables are cooking you can make the cheese mixture. In a medium bowl, combine the ricotta, 1 cup of the mozzarella, the remaining teaspoon of salt, the remaining ½ teaspoon of garlic granules, the remaining ½ teaspoon of Italian seasoning, and the onion granules. Stir well.
Spray the crockpot with cooking spray and dump in half of the can of crushed tomatoes. Break 2 or 3 lasagna noodles in half and layer them on top of the sauce, then finish the can of sauce on top of the noodles. Then add ⅓ of the vegetable mixture, and ⅓ of the cheese mixture. Repeat the layering two more times ending with lasagna noodles and the marinara sauce.
Put the lid on the crockpot and cook on high for 2 ½ hours or on low for 5 hours. When it's done, add the remaining cheese and cook until that is melted, about 5 more minutes. Top with fresh basil and serve.