Preheat oven to 325°F. Spray a non-stick loaf pan with cooking spray.

Mash bananas in a bowl, set aside.

In a medium bowl, combine flour, baking soda, and salt with a wire whisk. Set aside.

In a large bowl, cream butter and brown sugar with an electric mixer.

Add egg whites, bananas, apple sauce, and vanilla; beat at medium speed until thick. Scrape down sides of the bowl.

Add flour mixture, then blend at low speed until combined. Fold in chocolate chips. Do not overmix.

Pour batter into loaf pan; bake for 40 minutes, or until a toothpick inserted in the center comes out clean.