Heat the oven: Preheat to 425°F (220°C). Line a large sheet pan with parchment paper or lightly oil it for easy cleanup.
Prep the vegetables: In a large bowl, toss the sweet potato cubes, red onion wedges, and bell pepper strips with 1 tablespoon olive oil, 1/2 teaspoon salt, and half of the paprika, garlic powder, and pepper.
Season the chicken: Pat the chicken dry.
In a separate bowl, mix 1 tablespoon olive oil, the remaining paprika, garlic powder, onion powder, chili powder (if using), 1/2 teaspoon salt, and black pepper. Coat the chicken evenly.
Arrange on the pan: Spread the vegetables in a single layer, leaving space for the chicken. Nestle the chicken pieces among the vegetables so everything touches the pan for good browning.
Roast, then sauce: Roast for 15 minutes.
Remove the pan and brush the chicken generously with BBQ sauce. Toss the veggies lightly with any pan juices.
Finish roasting: Return to the oven for 10–15 minutes, until the chicken reaches an internal temperature of 165°F and the sweet potatoes are tender with crisp edges. If you want more caramelization, broil for 2–3 minutes, watching closely.
Brighten and rest: Drizzle the apple cider vinegar or lemon juice over the vegetables.
Let the chicken rest 5 minutes. Brush with a little extra BBQ sauce if you like.
Serve: Scatter chopped parsley or green onions over the top. Serve straight from the pan or plate it up with a side salad or steamed greens.