Preheat oven to 350 degrees F. Spray a 9 x 13″ baking dish with cooking spray and set aside.
Heat olive oil in a skillet over medium-high heat. Add onion, and saute until starting to brown, 5-8 minutes. Add rice, and saute 3 minutes longer, then transfer rice mixture to prepared baking dish.
Whisk together chicken broth, whipping cream, pumpkin, chili powder, and salt. Pour over rice mixture.
Arrange chicken pieces skin-side up over rice mixture, and sprinkle very liberally with seasoned salt. Cover tightly with foil, and bake in preheated oven for 60 minutes.
Remove foil. There will probably still be a lot of liquid left in the pan at this point. Return uncovered pan to oven, and bake for 30-45 minutes longer, or until almost all liquid is absorbed and chicken is cooked to an internal temperature of 165 degrees F. (A digital probe thermometer will be your best friend for this part.) Enjoy!