Preheat your oven to 350 degrees F. Grease an 8-inch loaf pan with cooking spray and set it aside.
In a medium bowl, whisk together the flour, baking soda, and salt.
In another bowl or a stand mixer, blend the oil and brown sugar until they are well combined. Add the eggs, sourdough starter discard, mashed bananas, and vanilla extract, mixing until smooth.
Slowly incorporate the dry ingredients into the wet mixture, ensuring to scrape down the sides of the bowl as needed. Gently fold in the chocolate chips.
Transfer the batter into the prepared loaf pan. Bake for about 55 minutes or until a wooden skewer inserted into the center comes out mostly clean, ensuring you do not overbake.
Allow the bread to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.