Preheat oven to 425°F. Mix brown sugar and seasonings in large bowl. Reserve 1 tablespoon. Brush pork tenderloin with 1 tablespoon of the oil. Sprinkle with remaining seasoning mixture. Place in center of large foil-lined shallow baking pan.
Toss apples, onions and remaining 1 tablespoon oil in medium bowl. Add reserved seasoning mixture; toss to coat well. Spread around pork in pan.
Roast 25 to 30 minutes or until pork is desired doneness. Slice pork and serve with apples and onions.