Preheat the oven to 350°F (177°C) and place the oven rack in the lower third position to ensure even baking. Grease a 9×5-inch loaf pan using nonstick spray and set it aside.

In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon. This will help distribute the dry ingredients evenly throughout the batter. Set aside.

In a large bowl, using a handheld or stand mixer with a paddle attachment, cream the softened butter and brown sugar together on high speed until the mixture is smooth and creamy, which should take about 2 minutes. Reduce the speed to medium, and add the eggs one at a time, making sure to beat well after each addition. Then, mix in the yogurt, mashed bananas, and vanilla extract until fully incorporated.

Gradually add the dry mixture to the wet ingredients, mixing on low speed. Be careful not to overmix; stir until just combined, ensuring there are no pockets of flour. If desired, gently fold in the chopped nuts.

Pour the batter into the prepared loaf pan, spreading it evenly. Bake for 60–65 minutes, loosely covering the top of the bread with aluminum foil after 30 minutes to prevent over-browning. The bread is done when a toothpick inserted into the center comes out clean or with just a few moist crumbs.

Once baked, remove the loaf from the oven and let it cool in the pan on a wire rack for 1 hour. Afterward, transfer the bread directly to the rack to cool completely before slicing and serving.

For storage, cover the banana bread and keep it at room temperature for up to 2 days, or refrigerate for up to 1 week. The flavors develop and improve over time, with day 2 yielding the best results.