In an electric mixer on medium speed mash 4 ripe bananas and blend until well mashed and no chunks remain. Then add the remaining wet ingredients ¼ cup sour cream, 2 eggs, and ½ cup melted butter.
In a separate bowl mix dry ingredients 2 cups flour, 1 teaspoon baking soda, ¾ cup brown sugar, and ½ teaspoon salt. On low speed or with a spatula by hand slowly add dry ingredients to bananas in the electric mixer. Mix until well incorporated
Pour your batter into a greased loaf pan topped with nuts (opt.) and place into the preheated oven. Bake for 60-70 minutes or until the toothpick comes out clean. My loaf pan is thin and long so if you have a shorter and thicker pan you will need to bake longer until the toothpick comes out clean.
Take out of oven let cool and flip out onto wire rack to cool to room temperture.