Preheat the oven to 350°F (175°C) and grease the cake 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, then stir in the vanilla extract.

Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, and mix until just combined.

Gently fold in the blueberries.

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

Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

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