Preheat your oven to 350°F and position the oven rack in the center. Spray a 9x5 inch loaf pan thoroughly with cooking spray, ensuring all corners and edges are coated to prevent sticking.

Combine the 2 cups flour, baking soda, salt, and cinnamon in a medium bowl. Whisk continuously for about 30 seconds to evenly distribute the leavening agents and spices, which prevents lumps and promotes even rising. Set this bowl aside.

In a large mixing bowl, whisk the cooled melted butter with the granulated sugar for approximately 1 minute until well blended and the texture becomes slightly lighter. Add the mashed bananas, eggs, Greek yogurt, and vanilla extract, then whisk energetically for 1 to 2 minutes until the mixture becomes smooth and fully emulsified.

Add the dry ingredient mixture to the wet ingredients. Using a rubber spatula or wooden spoon, gently fold the mixtures together until barely combined, stopping immediately when no white flour streaks remain visible. Avoid overmixing, as this develops gluten and produces a dense, tough texture.

Coat the fresh blueberries with the 1 tablespoon of flour, tossing to distribute evenly—this coating helps prevent the berries from sinking during baking. Gently fold the flour-coated blueberries into the batter using just a few strokes of your spatula. Transfer the batter to the prepared loaf pan and smooth the surface lightly.

Bake for 60 to 70 minutes, until a toothpick inserted into the center emerges with just a few moist crumbs attached (not wet batter). The bread will continue to cook slightly while cooling, so removing it at this stage ensures it remains moist and tender.

Allow the bread to cool in the pan for 10 minutes, which gives it time to set properly and hold its shape. Run a thin knife around the perimeter to release it, then invert onto a wire rack and let cool completely before slicing.