Step 1: Prepare Oven and Pan: Preheat oven to 350F (175C). Grease a 9x5 inch loaf pan or line it with parchment paper, leaving an overhang for easy removal.
Step 2: Combine Dry Ingredients: In a large bowl, whisk together the rolled oats, flour, baking soda, cinnamon, and salt. Ensure all ingredients are evenly distributed.
Step 3: Mix Wet Ingredients: In a separate bowl, mash the ripe bananas until smooth. Add the milk, maple syrup, melted coconut oil, and vanilla extract. Stir until well combined.
Step 4: Combine Wet and Dry: Pour the wet ingredients into the dry ingredients. Gently fold until just combined. Be careful not to overmix; a few lumps are okay. If adding walnuts or chocolate chips, fold them in now.
Step 5: Bake: Pour the batter into the prepared loaf pan. Spread evenly.
Step 6: Bake:Bake for 50-55 minutes, or until a wooden skewer inserted into the center comes out clean. If the top starts to brown too quickly, tent it loosely with foil.
Step 7: Cool: Let the bread cool in the pan for 10 minutes before transferring it to a wire rack to cool completely. Slice and serve.
Tips and Substitutions: For a gluten-free option, use a 1:1 gluten-free flour blend. If you don't have maple syrup, honey or agave nectar can be used as substitutes. For extra flavor, toast the oats lightly before adding them to the dry ingredients.