How to Make It
Preheat the oven to 400°. Brush four 1-cup ramekins with melted butter. Add 2 tablespoons of the sugar to 1 of the ramekins and rotate it to coat with sugar. Tap the excess sugar into another ramekin and repeat until all the ramekins are coated with sugar.
In a food processor, puree the bananas with the lime juice, egg yolk and 2 tablespoons of the sugar until smooth. Scrape the banana mixture into a large bowl.
In a medium stainless steel bowl, beat the egg whites with a pinch of salt until soft peaks form. Add the remaining 1 tablespoon of sugar and beat until firm and glossy. Using a rubber spatula, beat one-fourth of the beaten whites into the banana mixture, then gently fold in the remaining whites. Spoon the soufflé mixture into the prepared ramekins and tap them lightly on a countertop. Transfer the soufflés to a baking sheet and bake in the center of the oven for about 15 minutes, or until golden brown and risen. Serve at once.