Preheat oven to 350 degrees F. Coat a loaf pan with cooking spray and set aside.
In a medium-size mixing bowl, combine flour, baking soda and salt.
In a separate mixing bowl (or stand mixer) beat oil and sugar until well combined. Beat in eggs, sourdough starter discard, bananas and vanilla.
Gradually beat in flour mixture, scraping down sides of bowl as necessary. Fold in chocolate chips.
Pour batter into prepared pan. Bake for 55 minutes or until wooden pick inserted in center comes out mostly clean. Be careful not to overbake.
Let cool in pan 10 minutes then remove to wire rack to cool completely.