Preheat the oven to 350 F. Line and butter a 9x5" loaf pan.
In a bowl, combine the flour, baking soda, salt, and cinnamon. Whisk together and set aside.
In another bowl, whisk together the mashed bananas, melted butter, sugars, and buttermilk. Add the eggs, one at a time, whisking to fully incorporate. Add the vanilla.
Combine the wet and dry ingredients, along with the chopped pecans. Mix until combined, but take care to not over mix.
Pour the batter into the prepared pan, and top with the whole pecan halves. Bake for 65-75 minutes, or until a cake tester comes out dry. If the top is browning too quickly, tent with foil until the cake is done.
Allow to cool 10 minutes in the pan before removing to a cooling rack.
Recipe by The Kitchen Paper at http://c02.ddd.mwp.accessdomain.com/pecan-banana-bread/