Preheat oven to 350°F (175°C) and grease a loaf pan.

In a bowl, mash the bananas until smooth. Mix in melted butter, sugar, eggs, and vanilla extract until combined.

In another bowl, whisk together flour, baking soda, and salt. Gradually add to the wet mixture, folding gently.

Fold in chopped strawberries carefully.

For crumb topping: Combine brown sugar, flour, cinnamon, and cold butter until crumbly; sprinkle over batter.

Bake for about 55 minutes or until a toothpick comes out clean. Let cool before slicing.