Preheat the oven to 350°F (175°C) and grease a loaf pan.

In a mixing bowl, whisk together the dry ingredients: flour, baking powder, baking soda, and salt.

In another bowl, combine melted butter and sugar, then add eggs and vanilla extract, mixing well.

Stir in the buttermilk until smooth.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Gently fold in the blueberries, being careful not to overmix.

Pour the batter into the prepared loaf pan and smooth the top.

Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.

Let the bread cool in the pan for 10 minutes before transferring to a wire rack to cool completely.