Begin by preheating your oven to 350 degrees F. Spray the bottom of two 9x5" loaf pans with baking spray.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt*. Set aside.
In a large bowl, with an electric mixer, beat the sugar and butter flavor shortening until combined. Next, beat in the eggs and vanilla. Finally, add the bananas and beat until well combined.
Add the dry ingredients and stir with a spatula until just combined.
To create any of the banana bread variations, gently fold in the additional ingredients until just combined but evenly distributed.
Bake for 50 to 60 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and cool in pans for about 10 minutes. Remove from the pans to continue cooling on a wire rack.
Notes
*For traditional banana bread (without the variations), add 1 teaspoon cinnamon to the dry ingredients.