Preheat the oven to 350°F (175°C). Grease the loaf pan with butter or cooking spray.
In a large mixing bowl, combine the flour, sugar, baking powder, baking soda, and salt. Whisk until well mixed.
In a separate bowl, whisk together the buttermilk, melted butter, eggs, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients, stirring gently until just combined. Do not overmix.
Fold in the toasted pecans, reserving a few for topping if desired.
Pour the batter into the prepared loaf pan and smooth the top. Sprinkle additional pecans on top if you like.
Bake for 45 minutes or until a toothpick inserted into the center comes out clean.
Allow the pecan bread to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.