Preheat the oven to 350 degrees Fahrenheit. Grease a 9 x 5-inch pan and lightly dust it with flour.
First, mash the bananas very well with a fork. You should end up with 2 cups of mashed bananas, about 460 grams. Add the brown sugar and vanilla to the mashed bananas and blend with a hand held mixer.
Add the eggs one at a time and mix well. Add the sourdough discard to the batter, and mix with the handheld mixer.
In a separate large bowl, add the all-purpose flour, baking soda, and salt. Whisk well.
Slowly add the dry and wet ingredients, stirring with a spatula until incorporated.
Add the yogurt, oil, and miniature chocolate chips to the batter. Use a spatula to mix ingredients together until just combined. Avoid over mixing or your bread will be tough.
Pour batter into the prepared pan. Bake for 55-60 minutes or until a toothpick or skewer inserted into the bread comes out clean.
Let the bread rest for 10 minutes, then remove and let the bread finish cooling on a rack. For best results allow the bread cool completely before eating.