Melt butter and add sugar and mix well.

Then add the eggs and vanilla and blend it all together.

In a separate bowl, combine flour, baking soda, and salt and mix together.

Stir into the butter mixture until smooth.

Finally, fold in the sour cream and add the walnuts and bananas that have been mashed. Mix all together well.

Put into a loaf pan that has been sprayed with cooking spray.

Cook in oven that was preheated to 350 degrees. Cook for 60 minutes or until a toothpick inserted comes out clean.

Let cool in the bread pans for 10 minutes.

Use a knife around the edges to loosen the bread from the pan.

Let cool before cutting.