Preheat broiler. Chill mixer beaters and bowl in freezer, allowing 5 to 10 minutes for this before you start. Start whipping cream at medium speed. Meanwhile, hull the strawberries, washing if only sandy. Spread in a flameproof baking dish, halving any that are large. When cream holds stiff peaks, spread over strawberries. With your fingers, crumble brown sugar over cream, spreading as evenly as possible. Broil very close to heat until sugar has melted and cream starts to brown, 3 to 4 minutes. Serve at once.