Start by preheating your oven to 400°F (200°C). Place the sweet potatoes on a baking sheet and roast them for about 45 minutes or until they are soft and tender.
In the meantime, heat the olive oil in a large skillet over medium-high heat. Add the ground turkey and cook, breaking it apart with a spatula, until browned.
Once the turkey is nicely cooked, mix in the minced garlic, cumin, smoked paprika, oregano, and chili powder. Sauté for another minute until aromatic.
Add the diced tomatoes (including their juices), grated zucchini, chopped spinach, and if using, the black beans and corn. Stir everything together and let it simmer for about 5-8 minutes, allowing the vegetables to soften and the flavors to meld.
After roasting, let the sweet potatoes cool for a few minutes. Slice them lengthwise, and use a fork to fluff the insides gently. Drizzle with lime juice and season with salt and pepper.
Stuff each sweet potato generously with the turkey and vegetable mixture, topping them off with a sprinkle of shredded cheddar cheese.
Return the stuffed potatoes to the oven and broil for about 3-5 minutes, or until the cheese is melted and slightly bubbling.