Preheat oven to 350°F (175°C). Grease and flour a 9x5 inch loaf pan, or line with parchment paper leaving an overhang on the long sides for easy lifting.

In a large mixing bowl, whisk together the 1 3/4 cups all-purpose flour, granulated sugar, light brown sugar, baking soda, salt, and ground cinnamon until well combined. Set aside.

In a separate medium mixing bowl, mash the very ripe bananas until mostly smooth with some small lumps remaining (about 1 cup). Add the lightly beaten eggs, melted butter, vanilla extract, and sour cream. Whisk until thoroughly combined.

Pour the wet ingredient mixture into the dry ingredient mixture. Using a rubber spatula, mix until just combined. Be careful not to overmix; a few streaks of flour are okay. Overmixing will result in tough bread.

In a small bowl, toss the diced fresh strawberries and semi-sweet chocolate chunks with 1 tablespoon of all-purpose flour. This helps prevent them from sinking to the bottom of the loaf. Gently fold the floured strawberries and chocolate chunks into the batter until evenly distributed.

Pour the batter into the prepared loaf pan and spread evenly. Bake for 55-70 minutes, or until a wooden skewer or toothpick inserted into the center comes out clean or with a few moist crumbs attached (no wet batter). If the top starts to brown too quickly, you can loosely tent it with aluminum foil during the last 15-20 minutes of baking.

Once baked, remove the loaf pan from the oven and let it cool in the pan on a wire rack for 10-15 minutes. After cooling slightly, use the parchment paper overhang or a knife around the edges to carefully lift the bread out of the pan. Transfer to the wire rack to cool completely before slicing and serving. This ensures the bread is firm and holds its shape.