Step 1: Preheat and Prepare : Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan with butter or nonstick spray, and line with parchment paper for easy removal.

Step 2: Mix the Dry Ingredients : In a medium bowl, whisk together flour, baking soda, baking powder, salt, and cinnamon. Set aside.

Step 3: Mash the Bananas : In a large mixing bowl, mash the ripe bananas until smooth with a fork or potato masher.

Step 4: Combine Wet Ingredients : Add melted butter, brown sugar, eggs, and vanilla extract to the mashed bananas. Whisk until everything is well combined and smooth.

Step 5: Combine Wet and Dry Mixtures : Add the dry ingredients to the wet mixture and stir gently using a spatula until just combined. Do not overmix — a few small lumps are fine.

Step 6: Add the Walnuts : Fold in the chopped walnuts (and chocolate chips if using).

Step 7: Pour and Bake : Pour the batter into the prepared loaf pan. Sprinkle a few extra walnuts on top for a beautiful crunchy finish. Bake for 55–65 minutes, or until a toothpick inserted in the center comes out clean.

Step 8: Cool and Slice : Let the bread cool in the pan for about 10–15 minutes, then transfer to a wire rack to cool completely before slicing.