Preheat the oven to 350°F (175°C) and measure out all of the banana bread ingredients.
Grease a 4” x 8” (10 x 20 cm) loaf pan with butter or vegetable shortening, making sure to coat all corners and edges.
In a stand mixer bowl, mash the peeled bananas with a masher or fork until completely smooth.
Stir the melted butter into the mashed bananas until well combined.
In a separate bowl, whisk the egg, then add the vanilla extract and mix again. Pour the egg mixture into the bananas and mix together using the stand mixer.
Add the flour, baking soda, sugar, and salt to the bowl, mixing for about 1 minute between each addition.
Fold in the chopped walnuts with a silicone spatula until evenly distributed.
Pour the batter into the prepared loaf pan and bake for 50–60 minutes, or until a toothpick inserted in the center comes out clean.
Let the bread cool in the pan for 10 minutes, then gently remove it and transfer to a wire rack to cool completely before serving.
Notes
Storing Banana BreadTo store banana bread: first, wrap it tightly in plastic wrap. Store the wrapped loaf at room temperature for up to 3-5 days. For longer storage, after the 3-day mark, transfer the wrapped loaf to the refrigerator to prolong its shelf life for up to 7 days. Always mark the date on the outside of the wrapping to keep up with freshness.To freeze banana bread: first, wrap it tightly in plastic wrap and then again in kitchen foil. Mark the date on the outside and store the wrapped banana bread in the freezer for up to 3 months. Defrost the bread in the fridge for a day, and when ready to eat, just microwave a slice.