PREP: Preheat the oven to 400 degrees F. Spray a 9x13-inch and an 8x8, or 9x9-inch baking dish with cooking spray and set aside. Use the size pan that will hold the zucchini halves without crowding.
ZUCCHINIS: Cut the zucchini in half lengthwise. Use a small spoon or 1-teaspoon measuring spoon to carefully scoop the flesh out, leaving a good border along the edges of the zucchini. Place the zucchini halves in the prepared baking dishes (See Note 1) and drizzle 1 tablespoon olive oil over them. Rub the oil into the zucchinis and add a small sprinkle of salt and pepper (the filling is salted, so just a pinch here!). Bake for 5 minutes, remove and set aside.
GROUND TURKEY: While the zucchini bakes, heat the remaining 1 tablespoon olive oil in a large skillet, add the diced onion, and cook 3-5 minutes or until onion is beginning to become translucent. Add in the garlic. Cook, stirring constantly, for 30 seconds. Add the spices and cook, stirring constantly, for 30 seconds. Move everything to the sides and add ground turkey to the middle of the pan. Using a wooden spoon, cook and stir, breaking up the turkey into small crumbles, until cooked through and no longer pink, about 5-7 minutes. Drain off any liquid if needed.
FILLING: Add in the fire-roasted crushed tomatoes and enchilada sauce. Stir, bring to a simmer and allow to simmer for 3-5 minutes. Stir in the frozen corn, black beans, and cilantro. Mix until combined.
FILL ZUCCHINI SHELLS: Spoon the meat mixture evenly into the zucchini shells; it should fill 10 medium-sized zucchini halves (See Note 2). Add the grated cheese evenly on top.
BAKE: Bake for 20-25 minutes, or until zucchini is crisp-tender (it should still have a bite to it, and not be mushy!) and cheese is melted. If desired, add additional fresh cilantro and fresh lime juice. Enjoy immediately.