How to Make It
Preheat oven to broil with oven rack in upper third of oven. Place banana, cut side up, on a small rimmed baking sheet covered with aluminum foil. Sprinkle banana evenly with brown sugar and cinnamon. Broil until sugar mixture is melted and bubbly, 2 to 3 minutes.
Place caramelized banana in a serving dish. Top with ice cream, and drizzle with hot fudge and caramel. Top with whipped cream, and sprinkle with walnuts.