Preheat the oven to 350ºF. Butter two loaf pans. (I butter generously.)
In a stand mixer, cream butter and sugar until light and fluffy.
Meanwhile, in a separate bowl, whisk together flour, baking soda and salt
With the mixer on low, add the eggs one at a time, beating after each addition. Add the vanilla, buttermilk and bananas.
Add the flour mixture and mix until just combined. Divide batter between the two prepared pans. Bake for approximately 1 hour
Remove from oven and turn loaves out onto cooling rack immediately. Let cool.