Position baking rack in middle of oven and preheat oven to 350°F. Grease and flour a 9- x 5-inch loaf pan; set aside.

Lightly spoon AP flour into measuring cups, level off, and pour into a medium bowl mixing bowl. Add the cinnamon, baking powder, baking soda and salt; whisk together until well blended.

In a large mixing bowl, beat together the butter, brown sugar and white sugar well, scraping sides and bottom of bowl as needed.

Beat in the eggs one at a time. Add the vanilla extract and mashed bananas and beat well. Add the sour cream and mix on medium speed just until incorporated.

By hand, stir in the dry ingredients just until incorporated. Do not over mix. Over-mixing will cause a tough texture and tunneling.

Stir in pecans.

Pour batter into prepared loaf pan. Bake for 50-60 minutes or until a toothpick inserted into the center of the loaf comes out nearly clean. Allow bread to cool in pan for 5 minutes, remove from pan and cool on wire rack. Store in a plastic bag at room temperature.