Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper.
In a large bowl, toss the diced sweet potatoes with olive oil, garlic powder, paprika, salt, and pepper until evenly coated. Spread them out on the prepared baking sheet in a single layer.
Roast the sweet potatoes in the preheated oven for 25-30 minutes, or until they are tender and lightly browned, stirring halfway through.
While the sweet potatoes are roasting, combine the shredded chicken and BBQ sauce in a saucepan over medium heat. Stir until the chicken is heated through and well coated with the sauce, about 5-7 minutes.
To assemble the bowls, divide the cooked brown rice or quinoa among four bowls. Top each with roasted sweet potatoes, BBQ chicken, corn, and sliced avocado.
Garnish with fresh cilantro before serving.