2 grapefruits, halved crosswise
4 tablespoons raw sugar
A kitchen torch
Trim 1/4"-1/2" of peel from bottom of each grapefruit half to stabilize the fruit and prevent it from rocking back and forth. Place grapefruit, cut side down, on paper towels to dry for 5 minutes. Invert grapefruit and sprinkle 1 tablespoon sugar evenly over exposed flesh of each grapefruit half. Using a kitchen torch, heat sugar until melted and beginning to turn dark amber.
Alternatively, preheat broiler. Transfer grapefruit, cut side up, to a rimmed baking sheet lined with foil. Broil grapefruit, watching closely to prevent burning, until the sugar is melted and beginning to turn dark amber, about 8 minutes. Let grapefruit cool before serving.