In a small bowl, mix together the olive oil, brown sugar, smoked paprika, garlic powder, onion powder, salt, and black pepper. Set aside.
Remove any excess fat from the chicken thighs, pat them dry with a paper towel, and place them in a large bowl. Pour the olive oil mixture over the chicken and toss to coat making sure to completely cover each chicken piece in the spice mixture.
Place the chicken thighs in a single layer in a 9x9 baking dish. Cook for 40 minutes until the chicken is cooked through, juices run clear and a meat thermometer inserted into the thickest part of the chicken reads 165F.
Allow the chicken to rest for 5 minutes before garnishing with fresh chopped parsley and serving.