Preheat the oven to 400°F (200°C). Toss the diced sweet potatoes with olive oil, smoked paprika, cumin, garlic powder, salt, and black pepper on a baking sheet. Spread them out in a single layer and roast for 25-30 minutes, or until tender and slightly caramelized, stirring halfway through.

While the sweet potatoes are roasting, cook the quinoa. In a medium saucepan, combine the rinsed quinoa and vegetable broth. Bring to a boil, then reduce heat to low, cover, and simmer for about 15 minutes or until the quinoa is fluffy and the liquid is absorbed. Remove from heat and let it sit covered for 5 minutes, then fluff with a fork.

In a large bowl, combine the cooked quinoa, roasted sweet potatoes, black beans, corn, and chopped cilantro. Mix well to combine all ingredients.

Warm the tortillas in a dry skillet over medium heat for about 30 seconds on each side or until pliable.

To assemble the tacos, spoon the sweet potato and quinoa mixture onto each tortilla. Top with diced avocado and a squeeze of fresh lime juice.

Serve immediately with extra lime wedges on the side.