Preheat Oven to 350°F.
Butter and line 2 bread pans, Over lining so the paper makes handles to pull the banana bread out.
Cream together: butter and sugars until light and fluffy.
In a separate bowl, combine: flour, baking soda and salt.
To the butter mix, add eggs, one at a time, mixing well after each addition.
Add: buttermilk, vanilla and mashed bananas.
Add the flour mix in 2 additions, mix until just combined.
divide the batter evenly between both bread pans, and add the halved bananas to the top of each loaf.
Bake for 1-1.5 hours or until toothpick comes out clean.
Remove from oven, let cool in pans for 5 minutes before turning out onto a cooling rack and covering until cool.