01 -
Preheat the oven to 350°F (180°C) and grease a 9×5-inch loaf pan.
02 -
In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and granulated sugar.
03 -
In a separate bowl, beat the melted butter, egg, buttermilk, and vanilla extract until smooth.
04 -
Gradually add the wet mixture to the dry ingredients, stirring gently until just combined, avoiding overmixing.
05 -
Pour the batter into the prepared loaf pan evenly.
06 -
Mix granulated sugar and cinnamon for the topping, sprinkle evenly over the batter, then drizzle with melted butter.
07 -
Bake for 45 to 50 minutes in the preheated oven, until a toothpick inserted into the center comes out clean.