Cut the baked sweet potatoes in half and fluff their centers with a fork to create slight reservoirs in each. Set aside.
Heat the oil in a large skillet over medium-high heat. Add the ground turkey and cook, breaking it up with a spoon, until it's browned, about 8 minutes. Add the black beans, corn, salsa and taco seasoning and cook, stirring, until they are heated through, 3 to 4 minutes. Remove the skillet from the heat.
Spoon the turkey taco mixture into the center of each sweet potato. Top each with avocado, a dollop of sour cream, some green onion and cilantro. Serve immediately or store in the refrigerator, covered, for up to 3 days.