Preheat the oven to 375 degrees F. Measure one cup of marinara sauce and set aside.
Trim the ends from the zucchini and slice them in half lengthwise. Using a teaspoon, scrape the inside of the zucchini forming a cavity, being careful not to cut through.
Place the zucchini boats in a 9 x 13" baking dish and add a cup of water. Cover with foil then bake for 20 minutes or until just slightly fork tender. Remove from oven, remove foil and set aside to cool slightly.
While the zucchini is cooking, add the olive oil to a skillet and place over medium heat. Add the ground turkey, onions, peppers, and garlic to the pan, and stir until fully combined. Cook, stirring to break up the ground turkey as it cooks. Cook until the meat is cooked and the vegetables have softened. If there is too much grease, drain off as much as possible. and return skillet to the heat.
Add the remaining 2 cups marinara sauce, parsley and spices and simmer over low heat for 15 minutes. Taste and adjust the spices if necessary.
Remove the zucchini from the baking dish and drain off the water. Pour the 1 cup marinara on the bottom of the dish and place the zucchini on top of the sauce.
Fill the zucchini cavities with the meat sauce. If you have extra, add it around the zucchini or save it to enjoy with pasta another day. Cover the dish with foil and bake for 20 minutes. or until zucchini is fork tender.
Remove dish from oven and set the oven to broil. Remove the foil then sprinkle the mozzarella cheese, then the parmigiano-reggiano cheese, and then the breadcrumbs evenly over the six zucchini boats.
Place dish in the oven and broil for approximately 2 minutes, with the door open, until the cheese has melted and golden in colour.