Preheat oven to 350°F. Spray a 9x13-inch baking dish with nonstick cooking spray.
Trim the ends of zucchini. Slice in half horizontally. Use a small spoon to clean out the centers of the flesh carefully. Place zucchini in pan.
Place turkey in a large skillet over medium heat. Cook, breaking up chunks, until almost all the pink is gone. Drain fat.
Add onion and garlic to the turkey and continue to cook on medium heat until the onion is soft, 3-5 minutes. Add the mushrooms and seasonings. Cook 3-5 minutes, then stir in the pasta sauce. Cook just a few more minutes to meld the flavors and taste test for seasoning.
Fill the zucchini boats evenly with the turkey mixture.
Cover the pan with foil and bake for 25 minutes. Remove the foil and continue to bake until the zucchini is almost your desired tenderness. Top with cheese and cook just until melted.
Serve hot. Store leftovers in the refrigerator for up to 3 days.