Soak cedar plank according to manufacturer’s directions. Drain and pat dry.
Preheat grill to medium-high heat (400°F to 450°F) for 15 minutes. Reduce heat to medium-low (300°F to 325°F). Meanwhile, mix brown sugar and chili powder in small bowl. Brush salmon with oil. Rub seasoning mixture on flesh side of salmon. Place salmon, skin-side down, on cedar plank.
Place cedar plank with salmon on grill. Cover grill. Grill 30 to 40 minutes or until fish flakes easily with a fork.
Cooking over a campfire? Prepare cedar plank and fish as directed. Arrange hot coals to one side of campfire and carefully place grill grate over top. Place cedar plank with salmon over indirect heat (the side without the flames). Tent with foil for even cooking and smoky cedar flavor. Cook as directed, rearranging hot coals as needed to maintain indirect heat.