01 - Preheat oven to 350°F. Grease and flour a 9x5-inch loaf pan or line with parchment paper.
02 - Whisk mashed bananas, eggs, oil or butter, yogurt or sour cream, sugar, and vanilla extract in a large bowl until thoroughly blended.
03 - Sift flour, baking soda, salt, and cinnamon together in a separate bowl.
04 - Gently fold dry ingredients into wet mixture, mixing just until incorporated. Avoid overmixing to prevent dense texture.
05 - Stir in nuts and/or chocolate chips if desired.
06 - Transfer batter to prepared loaf pan and level the surface evenly.
07 - Bake for 50-60 minutes until a toothpick inserted into the center emerges clean or with a few moist crumbs.
08 - Let cool in pan for 10 minutes, then remove to wire rack to cool completely before slicing.