01 - Preheat oven to 350°F. Thoroughly grease a 9x5-inch loaf pan or line with parchment paper.
02 - In a large bowl, mash bananas until smooth. Blend in melted butter, eggs, and vanilla extract until homogeneous.
03 - In a separate bowl, whisk together flour, granulated sugar, baking soda, and salt.
04 - Add dry mixture to wet mixture, stirring gently until just incorporated.
05 - Carefully fold in diced strawberries and, if desired, chopped walnuts or pecans. Avoid overmixing.
06 - Transfer batter into prepared loaf pan, spreading evenly.
07 - Bake in preheated oven for 50 to 55 minutes, or until a toothpick inserted at the center emerges clean.
08 - Allow loaf to cool in pan for 10 minutes, then release and place on a wire rack to cool fully before slicing.