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

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

In another bowl, cream the softened butter and sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Add the dry ingredients to the wet ingredients alternately with the buttermilk, starting and ending with the dry ingredients.

Gently fold in the blueberries.

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

Bake in the preheated oven for 55-60 minutes, or until a toothpick inserted into the center comes out clean.

Allow to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.