Grease a loaf pan with the oil of your choice (whatever oil is going in the bread). Preheat the oven to 350 degrees F.

Make the vegan buttermilk. Combine the plant milk and apple cider vinegar. Leave to rest for 5 minutes.

In a large bowl, mash the brown sugar, olive oil, plant milk, bananas, vanilla extract, miso paste, soy sauce, and vegan yogurt. Mash with a fork or potato masher until the bananas are mostly mashed. The bananas don't need to be completely smooth; you want some banana chunks!

In a separate bowl, sift and whisk together the flour, salt, baking soda, and baking powder.

Add the dry ingredients to the wet, and fold until combined. If using the add-ins, add them halfway through folding in the dry ingredients.

Add the batter to the greased loaf pan.

Bake for 25 minutes, rotate the pan, and bake for another 25 minutes or until a toothpick comes out mostly clean. The edges will be slightly browned and caramelized.

Set the pan on a cooling rack. Allow to cool until the pan is cool enough to handle. Then, flip the bread out and allow it to cool completely on the cooling rack. You may need to slide a butter knife or offset spatula around the pan before flipping.