Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
In a large bowl, toss cubed sweet potatoes with olive oil, smoked paprika, garlic powder, salt, and pepper until evenly coated.
Spread the sweet potatoes in a single layer on the prepared baking sheet and roast for 20-25 minutes until tender and caramelized.
While potatoes roast, heat a non-stick skillet over medium-high heat. Add the chicken cubes and cook for 8-10 minutes, stirring occasionally, until the internal temperature reaches 165°F (74°C).
Reduce the skillet heat to low, pour the barbecue sauce over the chicken, and stir for 2 minutes until the sauce is thickened and the chicken is fully glazed.
Assemble the bowls by dividing the cooked grains, roasted sweet potatoes, BBQ chicken, black beans, and corn into four separate containers.
Top each bowl with avocado slices and fresh cilantro before serving.