Preheat oven to 350 degrees.
Grease and flour three loaf pans (I prefer Pyrex).
Add baking soda to buttermilk - let sit till needed.
Cream butter and sugar together in electric mixer.
Add eggs and combine till thoroughly mixed.
In large bowl mix together flour, baking powder, and salt. Mix together.
To creamed butter and egg mixture alternately add buttermilk (with baking soda added in) and rest of dry ingredients and mix till well combined.
Finally, add mashed bananas and chopped nuts to mixture. Your mixing bowl will be getting very full so mix slowly.
Pour batter evenly into the three prepared loaf pans and bake for approximately 1 hour and 40 minutes in oven. NOTE: cooking times may vary according to oven or altitude. Check approximately 1 hour into cooking and adjust accordingly. 1 hr and 40 minutes works perfectly for us but I've had reports of bread cooking much faster for some readers.
Bake until inserted toothpick comes out clean. Once done, remove from oven and let cool thoroughly before removing from loaf pans.
This recipe freezes well. However, do let it cook thoroughly before wrapping it for freezer. Otherwise you'll get condensation on the inside of your wrapping materials as the bread cools in the freezer.
To serve, remove from freezer and let thaw naturally on the counter or cut and thaw slices in the microwave for approx 30 seconds.