01 - Preheat oven to 350°F (175°C). Grease a 9x5 inch loaf pan with butter or nonstick spray.
02 - In a large bowl, whisk together the flour, baking soda, and salt until evenly blended.
03 - In a separate bowl, mash bananas thoroughly. Add melted butter, brown sugar, eggs, and vanilla extract. Stir until smooth.
04 - Pour the wet mixture into the dry ingredients. Stir just until combined; avoid overmixing.
05 - Fold chocolate chunks into the batter gently to distribute evenly.
06 - Pour batter into prepared loaf pan. Smooth the top and bake for 55-65 minutes or until a skewer inserted into the center emerges clean except for melted chocolate.
07 - Allow bread to cool in the pan for 10 minutes. Transfer to a wire rack to cool completely before slicing.