01 - Preheat oven to 350°F (175°C) and grease a 9x5-inch loaf pan or line with parchment paper.
02 - In a large mixing bowl, mash bananas until smooth. Add melted butter, eggs, and vanilla extract, stirring until fully incorporated.
03 - In a separate bowl, whisk together all-purpose flour, granulated sugar, baking soda, and salt.
04 - Gradually add dry ingredients to the banana mixture, stirring gently until just blended.
05 - Gently fold in diced strawberries and, if desired, chopped walnuts or pecans. Take care not to overmix.
06 - Pour batter into prepared loaf pan and smooth the top.
07 - Place pan in oven and bake for 50 to 55 minutes, or until a toothpick inserted into the center emerges clean.
08 - Allow bread to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.