Preheat the oven to 350°F (175°C) and grease a loaf pan.

In a mixing bowl, mash the ripe bananas until smooth.

Add sour cream, softened butter, sugar, eggs, and vanilla extract to the mashed bananas. Mix until well combined.

In another bowl, whisk together the flour, baking soda, and salt.

Gradually add the dry ingredients to the wet ingredients, stirring until just combined.

Pour the batter into the prepared loaf pan.

Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center comes out clean.

Remove from the oven and let cool in the pan for 10 minutes before transferring to a wire rack to cool completely.