Better Banana Bread

16 ounces, all-purpose flour
1 tablespoon baking powder
½ tablespoon baking soda
1 teaspoon salt
8 ounces unsalted butter or shortening at room temperature (I use butter flavored Crisco)
20 ounces brown sugar
4 large eggs
2 teaspoons vanilla
1 cup buttermilk
20 ounces ripe bananas, mashed

Preheat oven to 350°. Grease three loaf pans.
Sift together the flour, baking powder, baking soda and salt. Set aside.
Using paddle cream the butter and brown sugar on medium speed until smooth and creamy, about 2 minutes.
Mix in eggs, one at a time, waiting for each to incorporate completely before adding the next. Mix in the vanilla and continue mixing for 2 to 3 minutes until mixture is light and fluffy.
Mix in 1/3 of the flour mixture, then 1/3 of the buttermilk, then 1/3 of the bananas, repeating until all the ingredients have been added. Mix until the flour is just absorbed and the batter is smooth.
Pour batter into pans, filling no more than two-thirds.
Bake for 45 minutes then reduce oven to 325° and bake an additional 15 minutes. Internal temperature should be between 180° and 185°. Skewer poked in center should come out clean.
Let loaf cool in the pan for 10 to 15 minutes then turn out onto a rack to cool for at least 1 hour before slicing.