Preheat the oven to 375°F (190°C) and line a muffin tin with paper liners.

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

In another bowl, combine the wet ingredients: melted butter, buttermilk, eggs, and vanilla extract. Mix well.

Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.

Gently fold in the blueberries.

Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full.

Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean.

Remove from the oven and let cool in the pan for 5 minutes before transferring to a cooling rack.