Preheat your oven to 350°F (175°C). Grease and flour a 9x5-inch loaf pan.
In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and cinnamon until well combined.
In another bowl, cream the softened butter with an electric mixer until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the butter mixture, alternating with the buttermilk. Mix until just combined. Fold in the chopped pecans.
Pour the batter into the prepared loaf pan and smooth the top. Bake for 55-65 minutes, or until a toothpick inserted in the center comes out clean.
Let the bread cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.