Bake Sweet Potatoes: Preheat oven to 350°F or 180°c. Place the sweet potatoes on a baking tray and poke 1-2 times with a fork. Bake for 45 minutes, or until soft and cooked through. The exact cooking time will depend on the size of the sweet potatoes.
Cook Onion and Bell Pepper: When the sweet potatoes have around 10 minutes baking time left, heat the olive oil in a frying pan over a medium-high heat. Add the onion and bell pepper and cook, stirring, for around 5 minutes or until softened.
Add Spices: Add the cumin, paprika, oregano, onion powder and garlic powder and cook, stirring, for 1-2 minutes or until fragrant. Season with a pinch of salt and pepper.
Add Corn and Black Beans: Add the corn and black beans and stir to mix. Cook for 1-2 minutes until heated through.
Stuff Sweet Potatoes: Slice the sweet potatoes open lengthways using a sharp knife. Divide the black bean corn mixture between the sweet potatoes.
Serving: Top with the avocado, yogurt, sour cream or another sauce of choice, and cilantro. Serve with the lime wedges and hot sauce, if desired.