Heat your oven to 350°F and position the rack in the center. Lightly coat a 9x5 inch loaf pan with cooking spray, making sure to get into all the corners and edges. This prevents sticking and ensures your bread releases cleanly after baking.
In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon. Whisk for about 30 seconds to evenly distribute the leavening agents and spices throughout the flour—this prevents lumps and ensures even rising. Set this mixture aside.
In a large bowl, whisk together the cooled melted butter and granulated sugar for about 1 minute until well combined and slightly lighter in texture. Add the mashed bananas, eggs, Greek yogurt, and vanilla extract, then whisk vigorously for 1-2 minutes until the mixture is smooth and well emulsified. I like using Greek yogurt here because it adds tanginess and moisture without making the bread heavy—it's the secret to keeping this tender and not overly dense.
Pour the dry ingredient mixture from Step 2 into the wet mixture from Step 3. Using a rubber spatula or wooden spoon, gently fold everything together until just combined—stop as soon as you don't see any white streaks of flour. Overmixing develops gluten and creates a dense, tough crumb, so resist the urge to fully blend this.
Toss the fresh blueberries with the 1 tablespoon of flour—this coating prevents them from sinking to the bottom of the loaf during baking. Gently fold the coated blueberries into the batter from Step 4 with just a few strokes of your spatula. Pour the batter into the prepared pan from Step 1 and smooth the top slightly. Bake for 60-70 minutes until a toothpick inserted into the center comes out with just a few moist crumbs (not wet batter). I find that banana bread continues to cook slightly as it cools, so pulling it out when there are still a few moist crumbs ensures it won't be dry.
Let the bread cool in the pan for 10 minutes—this allows it to set enough to hold its shape without being too delicate. Run a thin knife around the edges to loosen it, then turn it out onto a wire rack to cool completely before slicing. This method prevents the bread from cracking as it cools.