01 - Preheat the oven to 350°F. Grease a 9x5-inch loaf pan or line with parchment paper.
02 - In a large mixing bowl, mash the bananas until smooth. Add the melted butter, eggs, and vanilla extract. Stir until fully incorporated.
03 - In a separate bowl, whisk together the flour, granulated sugar, baking soda, and salt until well blended.
04 - Add the dry mixture to the wet mixture and stir gently until just combined. Avoid overmixing.
05 - Gently fold in the diced strawberries and, if using, the chopped walnuts or pecans.
06 - Pour the batter into the prepared loaf pan, spreading evenly.
07 - Place in the oven and bake for 50 to 55 minutes, or until a toothpick inserted in the center comes out clean.
08 - Remove from oven and cool in the pan for 10 minutes. Transfer to a wire rack and allow to cool completely before slicing.