Preheat your oven to 425°F (220°C), or 200°C if using a fan oven.
To ensure even cooking, lightly pound the chicken breasts to 1.5 cm (0.6 inches) thick at the thickest part. You can use a rolling pin, meat mallet, or even your fist for this step.
In a small bowl, mix together the seasoning ingredients (brown sugar, paprika, oregano, garlic powder, salt, and pepper).
Line a baking tray with foil and parchment paper for easy cleanup. Place the chicken breasts upside down on the tray. Drizzle one teaspoon of olive oil over each breast, then rub it in using your fingers. Sprinkle the seasoning mixture evenly over the chicken.
Flip the chicken breasts and drizzle with the remaining olive oil. Rub in the oil and season the other side of the chicken.
Bake for 18 minutes or until the surface is golden and the internal temperature reaches 165°F (75°C). You can use a meat thermometer to check the doneness.
Remove the chicken from the oven and transfer it to serving plates. Let it rest for 3 – 5 minutes before serving.
Optionally, garnish with freshly chopped parsley and enjoy with a side dish like garlic butter rice or a vegetable of your choice.