Collect all ingredients, measuring cups/spoons and whisk. Preheat oven to 325 degrees F.

Mash bananas with whisk. Stir bananas, oil, butter, eggs & sugar together in a large mixing bowl. Mix until fully blended.

Mix in remaining ingredients (except the chopped walnuts). Stir until the batter is fully mixed.

Add 1/2 cup of chopped walnuts to the batter. Make sure the chopped walnuts are evenly spread throughout the batter.

Pour finished batter into a nonstick bread pan. Smooth out the top of the batter within the bread pan. Bake in the oven at 325 F for 65-70 minutes.

Take out of oven and let the banana bread cool down in the bread pan for 10 minutes. Do not remove the banana bread from the bread pan during this 10 minute cool down period. Use oven mitts as the bread pan will be very hot coming out of the oven.

After 10 minutes, remove the banana bread from the bread pan. Place the banana bread on a cooling rack in order to completely cool. This cool down may take 1-2 hours. Gently slide a silicon spatula between the banana bread and the bread pan walls if the banana bread is stuck in the pan.