01 - Preheat oven to 350°F. Grease and flour a 9x5-inch loaf pan or line with parchment paper.
02 - In a large bowl, cream together softened butter and sugar until light and fluffy using electric mixer or whisk.
03 - Beat in eggs one at a time. Mix in sour cream and vanilla extract until fully incorporated.
04 - Stir mashed bananas into wet mixture until evenly distributed.
05 - In separate bowl, whisk together flour, baking soda, and salt until well blended.
06 - Gradually add dry ingredients to wet mixture. Mix gently until just combined. Do not overmix.
07 - Fold in walnuts, pecans, or chocolate chips if using.
08 - Pour batter into prepared loaf pan. Smooth top with rubber spatula.
09 - Bake for 55-65 minutes until toothpick inserted in center comes out clean or with few moist crumbs.
10 - Cool in pan for 10 minutes. Remove to wire rack to cool completely before slicing.