Preheat the Oven
Preheat your oven to 325°F (163°C). Position the oven rack in the center.Cream the Butter and Sugar
Using a hand or stand mixer, beat the softened butter and sugar until the mixture becomes light, fluffy, and pale yellow.Prepare the Wet Ingredients
In a separate bowl, whisk together the mashed bananas, eggs, and vanilla extract until well combined. Combine the Mixtures
Slowly add the banana mixture into the creamed butter and sugar, mixing until smooth.Mix the Dry Ingredients
In another bowl, whisk together the flour, baking soda, and salt. Make the Batter
Gradually add the dry ingredients to the wet mixture, alternating with the sour cream (or buttermilk). Mix just until everything is incorporated. Avoid overmixing to keep the bread tender.Prepare the Loaf Pans
Grease and lightly flour two standard loaf pans, tapping out any excess flour.Fill the Pans
Divide the batter evenly between the prepared pans and smooth the tops.Bake
Bake on the center oven rack for 50–60 minutes, or until a toothpick inserted into the center comes out clean.Cool
Allow the loaves to cool in the pans for 10 minutes before removing them. Carefully run a knife around the edges, then transfer the loaves to a wire rack to cool completely.
