A dd the chicken thighs, Italian dressing packet and the brown sugar to a 9 x 13" baking dish. Mix everything together until the chicken is evenly coated.
Place it into the center rack of the oven, uncovered, for 30 minutes
Baste the chicken in all the juice that it produced and place it back into the oven for another 30 minutes.
Finally, let the chicken rest for 5-10 minutes before serving. Spoon some of the sauce over it, garnish with parsley (optional) and enjoy!