Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.

Mix Wet Ingredients: In a large bowl, combine the mashed bananas, granulated sugar, brown sugar, melted butter, beaten egg, and vanilla extract. Mix well until smooth.

Add Baking Ingredients: Stir in the baking soda, salt, and ground cinnamon (if using) until combined.

Incorporate Flour: Gradually add the flour, mixing until just combined. Be careful not to overmix.

Fold in Strawberries: Gently fold in the chopped strawberries, distributing them evenly throughout the batter.

Pour into Pan: Pour the batter into the prepared loaf pan, smoothing the top with a spatula.

Bake: Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean (a few moist crumbs are fine).

Cool: Remove the bread from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely.