Preheat oven to 325 degrees and grease a loaf pan (or mini loaf pans, muffin cups)
In a small bowl, combine the flour, baking soda, and salt.
In a medium bowl, combine the egg, sugar, oil, milk, and vanilla.
Stir in the dry ingredients until just combined. *batter will be very thick
Add in the bananas and stir to combine.
Mix in walnuts (if using).
Pour batter into prepared loaf pan(s) and place into preheated oven.
Bake for 55-65 minutes if large loaf, 30-35 minutes if mini loaves, and 25 minutes if muffins.
Remove from oven once toothpick comes out clean when inserted in center of bread.
Allow to cool slightly, slice and enjoy!