How to Make It
Heat oven to 350° F. Butter an 8½-by-4½-inch loaf pan. In a medium bowl, whisk together the flour, baking powder, salt, and baking soda.
In a large bowl, mix together the butter, bananas, granulated and light brown sugars, eggs, and vanilla. Add the flour mixture and mix until just combined (do not overmix); fold in the pecans.
Spread the batter in the prepared pan and bake until a toothpick inserted in the center comes out clean, 50 to 60 minutes (tent with foil if top browns too quickly). Cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.