01 - Preheat oven to 400°F. Line a baking dish with parchment paper or lightly grease it.
02 - Slice zucchini in half lengthwise. Using a spoon, carefully scoop out the centers, leaving about a 1/4-inch shell. Reserve 1/2 cup of the zucchini flesh and finely chop it.
03 - Place zucchini halves in the prepared baking dish, cut side up.
04 - Heat olive oil in a large skillet over medium heat. Add onion and cook for 2-3 minutes until softened. Add garlic and cook for 1 minute more until fragrant.
05 - Add ground turkey to the skillet, breaking it up with a spoon. Cook until no longer pink, about 5-6 minutes.
06 - Stir in the reserved chopped zucchini flesh and spinach. Cook until the spinach wilts, 1-2 minutes.
07 - Remove skillet from heat. Stir in basil pesto, dried oregano, salt, and pepper until evenly combined.
08 - Spoon the turkey-spinach mixture evenly into the zucchini boats. Sprinkle with mozzarella and Parmesan cheese.
09 - Bake for 20-25 minutes, until zucchini is tender and cheese is golden and bubbling.
10 - Remove from oven and let rest for 5 minutes. Garnish with fresh basil and parsley before serving.