01 - Preheat oven to 350°F. Grease a 9x5-inch loaf pan and line with parchment paper.
02 - Whisk mashed bananas, eggs, melted butter, brown sugar, granulated sugar, and vanilla in large bowl until smooth.
03 - Sift flour, baking soda, salt, and cinnamon in separate bowl.
04 - Add dry ingredients to wet mixture. Fold gently until just combined—avoid overmixing.
05 - Fold in chocolate chips and walnuts. Reserve small portion for topping if desired.
06 - Pour batter into prepared loaf pan. Sprinkle reserved chocolate chips and walnuts over top.
07 - Bake 50–60 minutes until toothpick inserted in center comes out with few moist crumbs attached.
08 - Cool in pan 10 minutes. Transfer to wire rack to cool completely before slicing.