egg whites, beaten until frothy
Preheat oven to 350 degrees. Use a nonstick 8-inch square baking pan, or line baking pan with a baking pan liner or spray with vegetable cooking spray.
Place banana, orange juice and vanilla extract in blender or food processor and puree.
Sift sugar, flour, cocoa, baking powder and salt, if using, into a mixing bowl.
Stir in banana puree, egg whites and raisins.
Transfer batter to baking pan. Bake for 35 Minutes. Cool on wire rack. Cut into twelve squares.