Preheat oven to 375°F (190°C).
In a large non-stick skillet, brown the ground turkey with the diced onion and garlic over medium heat until the turkey is fully cooked.
Stir the grated zucchini and chopped spinach into the turkey mixture and cook for 2-3 minutes until the spinach is wilted.
Add the marinara sauce to the skillet, stir to combine, and simmer on low for 5 minutes.
In a medium mixing bowl, whisk the egg and combine it with the ricotta cheese, dried oregano, salt, and black pepper.
Spread 1/2 cup of the meat and vegetable sauce on the bottom of a 9x13 inch baking dish.
Place 3 whole wheat noodles over the sauce.
Spread 1/3 of the ricotta mixture over the noodles, followed by 1/3 of the remaining sauce and 1/2 cup of mozzarella cheese.
Repeat the layers twice more, finishing with the remaining sauce, mozzarella, and parmesan cheese.
Cover the dish tightly with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 15 to 20 minutes until the cheese is golden and bubbling.
Let the lasagna rest for 10 to 15 minutes before slicing to allow the layers to set.