In a large skillet, heat 1 Tablespoon olive oil. Add ground turkey and diced onion; season with salt and pepper.
Cook until turkey is browned, then add marinara sauce and mushrooms and simmer until mushrooms are tender. Keep warm over low heat.
In a medium mixing bowl, combine ricotta cheese, 2/3 of the Parmesan, 2/3 of the Mozzarella/Provolone mixture, eggs, Italian seasoning, and basil. Set aside.
Peel zucchini and slice it into thin discs.
Place zucchini in a single layer on the bottom of a 9x13 inch pan. Add half of the sauce, then add the cheese filling. Repeat with another layer of zucchini and the rest of the sauce. Top with reserved shredded cheese.
Bake, uncovered, at 350°for 45 minutes.
Remove from oven and garnish with fresh basil as desired.