Preheat the oven to 350ºF (175ºC) and lightly grease your loaf pan. In a medium bowl, combine the flour, baking soda, and salt.
With an electric mixer fitted with a paddle or a whisk, beat the butter and sugars together on medium speed for about 3 minutes, or until light and fluffy.
Add the eggs one at a time, mixing well after each addition. Add in the mashed bananas and vanilla and mix until well combined.
Slowly mix in the dry ingredients just until incorporated, being careful not to overmix. Fold in any add-ins as desired with a rubber spatula.
Pour into the prepared loaf pan and bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean. Remove from oven and let cool in the pan for a few minutes. Transfer to a wire rack, slice, and enjoy!