Preheat oven to 450.Spray large cookie sheet generously with cooking oil.Place Brussels sprouts on cookie sheet and sprinkle with cumin, chili powder and olive oil.Toss sprouts gently with hands.Spread sprouts out over cookie sheet so there's space between each one.Sprinkle 2-3 tablespoons brown sugar over all the Brussels sprouts.Roast for 20 minutes, until brown on the outside and slightly crispy.