Preheat the oven to 425°F and lightly coat a 9x13-inch baking dish with nonstick spray.
Trim the zucchini ends and slice into about 1/8-inch-wide strips using a mandolin or vegetable peeler.
Arrange half the zucchini slices in a single layer on a paper towel–lined baking sheet, sprinkle with 1/4 teaspoon of the kosher salt, then top with another paper towel and layer the remaining slices; sprinkle with another 1/4 teaspoon salt and let sit to draw out moisture.
Heat the olive oil in a deep skillet over medium heat. Add the ground turkey, onion powder, oregano, black pepper, red pepper flakes, and the remaining 1 teaspoon salt. Cook, breaking up the meat, until no pink remains.
Add the minced garlic to the cooked turkey and sauté about 30 seconds until fragrant, then remove the skillet from the heat.
Stir the ricotta, 1/3 cup of the shredded mozzarella, and 2 tablespoons of the grated Parmesan into the turkey until evenly combined to make the filling.
Spread a thin layer of marinara sauce across the bottom of the prepared baking dish.
Blot excess moisture from the top zucchini strips with fresh paper towels. Working with 4 strips at a time, arrange two strips as an “X” and the other two as a “+” over it to form a star-shaped base.
Spoon about 3 generous tablespoons of the turkey-ricotta filling into the center of the star. Fold two opposite ends of the zucchini over the filling, then fold the remaining ends to form a sealed packet; place seam-side down in the baking dish. Repeat with remaining strips and filling in a single layer.
Spoon the remaining marinara over the zucchini packets, then sprinkle with the remaining 2/3 cup mozzarella and 2 tablespoons Parmesan.
Bake for 15 minutes, or until heated through and cheese is melted. Sprinkle with chopped fresh basil, thyme, or parsley and serve hot.
