In a Dutch oven, cook onion, pepper, mushrooms, zucchini, carrots and sausage over medium heat until well browned. Add garlic about a minute or 2 before done. Stir in crushed tomatoes, tomato paste, tomato sauce, and water. Season with sugar, basil, oregano, 1 tablespoon salt, pepper, and parsley. Simmer, covered, for about 1 1/2 hours, stirring occasionally.
In a mixing bowl, combine ricotta cheese with egg, spinach, 1 cup of mozzarella, nutmeg and 1/2 teaspoon salt.
Preheat oven to 375 degrees F (190 degrees C).
To assemble, spread 1 1/2 cups of meat sauce in the bottom of a 9x13 inch baking dish. Arrange 1/2 of the noodles lengthwise over meat sauce. Spread with one half of the ricotta cheese mixture. Spoon 1 1/2 cups meat sauce over cheese then noodles then remaining cheese. Top with enough sauce to cover and sprinkle with the rest of the mozzarella. Cover with foil. Try to keep the foil slightly about the cheese to prevent sticking.
Bake in preheated oven for 25 minutes. Remove foil, and bake an additional 25 minutes. Cool for 15 minutes before serving.