Directions

1. Preheat oven to 350 degrees F. Coat a 9-by-5-inch loaf pan with cooking spray.
2. Whisk flour, baking powder, cinnamon, salt and baking soda in a medium bowl.
3. Beat sugar and butter (or coconut oil) in a bowl with an electric mixer on medium-high until well combined. Add eggs, one at a time, beating well after each adding. Add banana, buttermilk and vanilla; beat until combined. Add flour mixture; beat on low speed until just combined. Fold in walnuts (or chocolate chips), if using. Pour the batter into the prepared pan.
4. Bake until a toothpick inserted in the center comes out clean, 45 to 55 minutes. Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.