Preheat your oven to 425°F (220°C).
Toss the diced sweet potatoes with olive oil, cumin, chili powder, garlic powder, salt, and pepper in a large bowl.
Spread the sweet potatoes on a baking sheet in a single layer.
Roast the sweet potatoes for 25-30 minutes, stirring halfway through.
While the potatoes roast, heat black beans and corn in a saucepan over medium heat.
Once the sweet potatoes are cooked, remove them from the oven and set aside.
Assemble your taco bowls by layering sweet potatoes, black beans, corn, diced avocado, and chopped cilantro.
Serve your taco bowls with lime wedges on the side.