Preheat oven to 425 degrees Fahrenheit.
Pound chicken breasts so that they are about one inch thick for even cooking and place them in a baking pan.
Combine brown sugar, cajun seasoning, garlic powder, onion powder, chili powder, and smoked paprika.
Add olive oil to the seasoning mixture.
Evenly distribute the seasoning among the chicken breasts, making sure to season both sides. Use your fingers to press the seasoning into each chicken breast.
Bake for 17-20 minutes, or until the internal temperature of the chicken reaches 165 degrees Fahrenheit.
Optional: broil for the last few minutes until the chicken is golden brown.
Melt butter (microwaving for about 30 seconds will do the trick) and stir in dried parsley. Drizzle over the chicken.
Allow the chicken to rest for a few minutes before serving.