Preheat oven to 350°F (175°C). Grease a 9×5-inch loaf pan or a 9-inch square baking dish.
In a large bowl, whisk together melted butter, granulated sugar, and brown sugar until smooth. Add eggs, vanilla extract, and buttermilk, mixing until combined.
In a separate bowl, whisk flour, baking powder, baking soda, and salt. Gradually add dry ingredients to the wet mixture, stirring gently.
Stir in chopped pecans, ensuring even distribution.
Pour batter into the prepared pan. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Let cool in the pan for 10 minutes, then transfer to a wire rack. Slice and serve warm with butter, honey, or a dusting of powdered sugar.
