Preheat your oven to 400°F (200°C).
Slice the zucchini into 1/4-inch thick rounds and set aside.
In a large skillet over medium-high heat, add the olive oil and ground turkey. Cook until browned, breaking it up with a spatula.
Season the turkey with garlic powder, dried oregano, sea salt, and black pepper.
Stir the marinara sauce into the cooked turkey and simmer for 2 minutes.
In a small baking dish, spread a thin layer of the meat sauce on the bottom.
Arrange a layer of zucchini slices over the sauce, then top with more meat sauce. Repeat layers until all ingredients are used.
Sprinkle the grated Parmesan cheese evenly over the top layer.
Bake for 20-25 minutes until the zucchini is tender and the cheese is melted and golden brown.
Let rest for 5 minutes before serving to allow the juices to set.