Pre heat oven at 350.
Lightly coat bread loaf pan with butter or cooking oil.
Mash and blend the butter, bananas and eggs.
Pour cake mix on top of the banana mixture.
Add half of the walnuts to the mixture. Mix well and set aside.
Around 20 minutes in between spread the remaining walnuts on top of the cake mix and return pan to the oven.
Insert a toothpick into the middle of the pan to check if the cake is fully cooked.
Remove the cake from the oven, allow to cool before removing from the pan. Enjoy!