Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x5 inch loaf pan.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the mashed bananas.
In a separate bowl, sift together the baking soda, salt, cinnamon and flour. Stir into the creamed mixture alternately with the sour cream. Pour batter into the prepared pan.
Bake for 60 minutes, or until a toothpick inserted into the center of the loaf comes out clean.
Interesting Facts
This recipe makes one 9x5 inch loaf.
When making banana bread, it is best to use very ripe bananas for the sweetest flavor.