Scoop the interior out of the zucchini with a spoon or corer to create a boat shape.
Heat the olive oil in a large skillet or pan over medium-high heat, and once hot, sauté the onion for 4 minutes.
Add the ground turkey to the pan and sauté it for 5 to 7 minutes, breaking it up with a wooden spoon or spatula till it’s browned.
Add the Italian seasoning, garlic powder, salt, and pepper and cook for 30 seconds, stirring continuously.
Pour in the crushed tomatoes and stir to combine. Increase heat and allow to simmer for 3 minutes.
Place the zucchini in a large casserole dish (9x13 inch pan or larger) and spread a tablespoon of ricotta into the base of each zucchini. Then, divide the marinara mixture evenly between the boats*. Top each zucchini boat with several dollops of ricotta.
Cover the casserole dish with aluminum foil and bake for 30 minutes.
Remove the foil and turn the broiler on high. Broil the zucchini boats for 2 to 4 minutes until the ricotta is lightly toasted.
Remove the dish from the oven and top with Parmesan cheese and chopped basil. Serve immediately.
Notes
*Depending on the size of your zucchini you may have 1 to 1 ½ cups of leftover sauce. You can add it to the base of the pan and cook it alongside the zucchini, use it on an additional zucchini, or serve it with some pasta.