Preheat your oven to 375°F (190°C). Line a baking dish with aluminum foil and spray with cooking spray for easy cleanup.

In a small bowl, mix the garlic powder, paprika, onion powder, dried thyme, salt, and black pepper to create your spice rub.

Drizzle olive oil over the chicken breasts, then generously rub the spice mixture all over, including under the skin for maximum flavor.

Place the seasoned chicken breasts in the prepared baking dish, skin side up, making sure they don't overlap.

Bake in the preheated oven for 25 minutes.

Remove the chicken from the oven and generously brush each breast with BBQ sauce. If using brown sugar, you can sprinkle it over the sauce for added caramelization.

Return the chicken to the oven and bake for an additional 15-20 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the BBQ sauce has caramelized.

For extra saucy chicken, brush on another layer of BBQ sauce during the last 5 minutes of cooking.

Once done, remove from the oven and let rest for 5 minutes before serving. This helps the juices redistribute throughout the meat.

Serve hot with extra BBQ sauce on the side if desired.