Prep the oven and zucchini: Preheat your oven to 400°F (200°C).
Lightly grease a large baking dish. Trim the ends of the zucchini, slice them lengthwise, and use a spoon to scoop out the centers, leaving sturdy “boats” about 1/4 inch thick. Chop the scooped zucchini flesh and set it aside.
Parbake the boats: Arrange the hollowed zucchini cut-side up in the baking dish.
Sprinkle with a pinch of salt and a drizzle of olive oil. Bake for 8–10 minutes to soften slightly. This step helps avoid watery boats.
Cook the filling: While the zucchini pre-bakes, heat 1 tablespoon olive oil in a large skillet over medium heat.
Add the onion and bell pepper; cook 3–4 minutes until softened. Stir in the garlic and cook 30 seconds until fragrant.
Brown the turkey: Add the ground turkey, season with salt and pepper, and cook, breaking it up with a spatula, until no longer pink, about 5–7 minutes. Drain excess liquid if needed.
Add flavor and moisture: Stir in the chopped zucchini flesh, crushed tomatoes, tomato paste, Italian seasoning, smoked paprika, red pepper flakes, and cumin.
Simmer 4–5 minutes until thick and saucy. Taste and adjust salt and pepper.
Fill and top: Remove the zucchini from the oven. Spoon the turkey mixture into each boat, packing it in generously.
Sprinkle with Parmesan and then mozzarella.
Bake to finish: Return to the oven and bake 12–15 minutes, until the cheese is melted and lightly golden and the zucchini is tender but not mushy.
Garnish and serve: Let cool for a few minutes. Top with chopped parsley or basil. Serve with lemon wedges for a bright, fresh finish.