Heat barbecue to medium. Peel and halve pineapple into 6 ½-inch thick slices. Place chili pepper, 5 tsp of the sugar and 1 tsp of the paprika in mortar and pestle; grind until fine. Sprinkle over and press on pineapple slices and let marinate for 15 minutes.
Brush pineapple with remaining 2 tsp oil. Grill until caramelized, about 2 minutes. Serve immediately.
Notes
Maintaining a clean grill will prevent foods – like pineapple – from sticking. Turn heat to high after each use, then scrub with a grill-safe brush. Grease with layers of paper towel brushed in vegetable oil.