Preheat the oven to 350 F/176 C. In a small bowl whisk together the flour, salt, baking soda, and cinnamon.
In a large bowl cream together the butter and the sugar with a hand mixer or stand mixer. A wooden spoon will work too. Then add in the eggs and vanilla extract and mix those in. Scrape the sides of the bowl as needed throughout the whole batter making process.
Mix in the sour cream.
Peel and mash up the bananas using a fork or meat tenderizer. Then mix them into the batter until just combined. Remove the beaters and then scrape the sides of the bowl with a spatula and fold/mix in the dry ingredients until combined.
Grease and flour a 5x9 inch bread pan with shortening or butter. Cooking spray will work too. Then pour the banana bread batter into the pan. Bake for 50 to 60 minutes until a toothpick comes out clean in the middle, and it is golden brown on top. If your oven runs hot, set the temp to 325 F/162 C. You may need to bake it for 70 minutes.
After about 40 minutes check the bread, if it is getting too brown, you can add a piece of aluminum foil loosely on the top. Once baked allow the bread to cool for 20 to 30 minutes.
Remove the bread from the pan, slice and serve! Enjoy.