Preheat the oven to 425°F (218°C).
Place the chicken breasts between two pieces of plastic wrap or in a zip-top bag and gently pound with a meat mallet or rolling pin until they are an even thickness.
In a small bowl, combine the brown sugar, chili powder, paprika, Italian seasoning, and garlic powder to make the dry rub.
Rub the spice mixture evenly over both sides of each chicken breast.
Grease a 9 x 13-inch baking pan and arrange the seasoned chicken breasts in a single layer.
Bake in the preheated oven for 15–20 minutes, or until an instant-read thermometer inserted into the thickest part registers 165°F (74°C).
Remove the chicken from the oven and let it rest for 10 minutes before serving to allow the juices to redistribute.
