Preheat the oven to 425 degrees F. Spray a large baking dish or baking sheet with non-stick spray. Set aside.
Place the 4 chicken breasts between two sheets of parchment paper or plastic wrap. Pound each chicken breast to an even thickness; about a 1/2-inch. Pour the olive oil on the chicken breasts and rub to coat it all over them. Place chicken evenly on the prepared baking dish or sheet.
Pour the brown sugar, chili powder, garlic powder, onion powder, salt, and pepper in a small bowl. Whisk to combine. Rub this mixture all over both sides of the chicken breasts.
Bake in the preheated oven for 20 minutes or until the internal temperature of chicken reaches 165 degrees F. Carefully, remove from the oven. Allow chicken to stand for 5 minutes before serving. Enjoy!