Preheat the oven to 400°F (200°C).
In a mixing bowl, combine the barbecue sauce, brown sugar, olive oil, garlic powder, onion powder, smoked paprika, salt, and black pepper. Mix well until smooth.
Pat the chicken thighs dry with paper towels to ensure crispier skin.
Place the chicken thighs in a baking dish or on a sheet pan, skin side up. Brush the tops and sides with the barbecue mixture, ensuring an even coat.
Reserve about 2 tablespoons of the barbecue mixture for basting later.
Place the chicken thighs in the preheated oven and bake for 25 minutes.
After 25 minutes, remove the chicken thighs from the oven. Baste the tops with the reserved barbecue mixture.
Return the chicken to the oven and bake for an additional 10-15 minutes, or until the internal temperature reaches 165°F (74°C) and the skin is caramelized and crispy.
Once done, let the chicken rest for 5 minutes before serving.
Garnish with fresh parsley if desired, and serve hot with your favorite sides.