Preheat the air fryer. Set it to 380°F (193°C) for 5 minutes.
A hot basket helps the sweet potatoes crisp and the chicken sear lightly.
Prep the sweet potatoes. Toss the cubes with 1–1.5 tablespoons oil, smoked paprika, garlic powder, salt, pepper, and the optional cinnamon. Aim for even coating so they brown uniformly.
Start the sweet potatoes first. Add them to the basket in a single layer with a little space between pieces. Cook for 10 minutes, shaking halfway.
This gives them a head start so everything finishes together.
Season the chicken. Pat dry with paper towels. Mix smoked paprika, garlic powder, onion powder, chili powder (if using), salt, and pepper with 1 tablespoon oil. Rub over the chicken on all sides.
Make the sauce blend. In a small bowl, combine BBQ sauce with apple cider vinegar.
Add honey or maple if you want a touch more sweetness. This thins the sauce slightly so it doesn’t burn and helps it glaze nicely.
Add chicken to the basket. After the sweet potatoes have cooked 10 minutes, push them to one side or remove them to a plate. Place chicken in a single layer; avoid overlapping.
Return sweet potatoes to any open space if they fit without crowding.
Air fry the chicken. Cook at 380°F (193°C) for 8 minutes. Flip the pieces, then brush with half the BBQ sauce mixture.
Finish and glaze. Cook 4–6 more minutes, until the chicken reaches an internal temperature of 165°F (74°C). Brush with the remaining sauce and cook 1 additional minute to set the glaze.
Sweet potatoes should be tender with crispy edges; if they need more time, remove the chicken and give the potatoes 2–3 extra minutes.
Rest and garnish. Let the chicken rest for 3–5 minutes to keep it juicy. Toss sweet potatoes with a pinch of salt. Garnish with chopped parsley or green onions if you like.
Serve. Plate the glazed chicken alongside the sweet potatoes.
Add extra warm BBQ sauce on the side if desired.