Preheat oven to 400°F.

Coat 4 ramekins with butter-flavored cooking spray.

Place the ramekins on a baking sheet.

In a medium bowl, mash bananas and vanilla together.

Sift cornstarch and cocoa powder over bananas and stir well.

In another bowl, beat egg whites with sugar until soft peaks form.

Fold 1/3 of egg whites into banana mixture, then fold in the rest.

Spoon mixture into ramekins and wipe the top edges clean.

Bake for 15 minutes and serve immediately.