Preheat your oven to 350°F (175°C) and grease a 9x5 inch loaf pan.
Whisk the 1 1/2 cups flour, baking soda, and salt together in a medium bowl.
Mix the melted butter and sugar in a large bowl, then stir in the eggs, vanilla, and mashed bananas.
Toss the diced strawberries with the remaining 1 tablespoon of flour in a small bowl.
Fold the dry flour mixture into the wet ingredients until just combined, then gently fold in the flour-coated strawberries.
Bake for 55 to 65 minutes until a toothpick inserted in the center comes out clean. Cool in the pan for 15 minutes before transferring to a rack.