Preheat your oven to 350°F (175°C). Grease and flour your loaf pan or line it with parchment paper for easy removal.
In a large mixing bowl, combine the all-purpose flour, granulated sugar, brown sugar, baking powder, baking soda, salt, and ground cinnamon. Whisk until well mixed.
In another bowl, cream the softened butter until smooth. Add in the buttermilk, eggs, and vanilla extract. Mix until all wet ingredients are thoroughly combined.
Gradually add the wet mixture to the dry ingredients, stirring with a rubber spatula until just combined. Do not overmix.
Fold in the chopped pecans gently into the batter.
Pour half of the batter into the prepared loaf pan and drizzle half of the maple syrup over it. Add the remaining batter on top and drizzle the rest of the maple syrup on top.
Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center comes out clean.
Once done, remove the bread from the oven and let it cool in the pan for about 10 minutes. Then transfer it to a cooling rack to cool completely.