Adjust the oven rack to the lower third position and pre-heat the oven to 350°F.
Grease a 9 × 5-inch loaf pan or coat with nonstick spray; set aside.
In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon.
In a large bowl, using a handheld, or stand mixer fitted with a paddle or whisk attachment, beat the butter and brown sugar together on high speed until smooth and creamy, about 2 minutes.
On medium speed, add the eggs one at a time, beating well after each addition.
On medium speed, beat in the yogurt, mashed bananas, and vanilla extract until combined.
With the mixer running on low speed, slowly beat the dry ingredients into the wet ingredients until no flour pockets remain; do not overmix.
Fold in the nuts, if using.
Spoon the batter into the prepared baking pan and bake for 60 – 65 minutes.
Loosely cover the bread with aluminum foil after 30 minutes to help prevent the top and sides from getting too brown.
A toothpick, inserted in the center of the loaf, will come out clean when the bread is done.
Remove from the oven, set on a wire rack and allow the bread to cool completely in the pan.
Cover and store banana bread at room temperature for 2 days or in the refrigerator for up to 1 week.
Banana bread tastes best on day 2 after the flavors have settled together.
