Wash the sweet potatoes thoroughly and poke a few holes in each with a fork. Place them on a baking sheet lined with parchment paper. Bake in the preheated oven for 45-55 minutes, or until tender.
While the sweet potatoes are baking, heat a large skillet over medium heat. Add the ground turkey (or beef) and cook until browned, breaking it apart with a spatula. Drain any excess fat if needed.
Stir in the black beans, corn, diced tomatoes, taco seasoning, garlic powder, onion powder, salt, and pepper. Cook for an additional 5-7 minutes, stirring occasionally, until everything is heated through.
Once the sweet potatoes are done, remove them from the oven and let them cool for a few minutes. Carefully slice each potato in half lengthwise, creating a pocket for the filling.
Using a fork, gently fluff the insides of the sweet potatoes. Spoon the taco mixture evenly into each sweet potato half.
Top each stuffed potato with diced avocado and shredded cheddar cheese.
Return the stuffed sweet potatoes to the oven for an additional 5-10 minutes, just until the cheese is melted.
Remove from the oven and garnish with freshly chopped cilantro. Serve with lime wedges on the side for squeezing over the top.