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 pepper. Mix well until all ingredients are incorporated.
Pat the chicken thighs dry with paper towels and season them with salt and pepper.
Place the chicken thighs in the baking dish, skin side up.
Pour the barbecue sauce mixture over the chicken thighs, ensuring they are well coated.
Bake the chicken thighs in the preheated oven for 35-40 minutes. Halfway through cooking, baste the chicken with the sauce in the baking dish.
For a caramelized finish, switch the oven to broil for the last 3-5 minutes, keeping a close eye to prevent burning.
Remove the chicken from the oven and let it rest for 5 minutes before serving.
Garnish with fresh parsley if desired and serve with your favorite sides.