Preheat your oven to 375°F (190°C). This ensures that the muffins bake evenly and rise properly.

In a large mixing bowl, whisk together the dry ingredients: flour, sugar, baking powder, baking soda, and salt. This helps to evenly distribute the leavening agents and prevents clumping.

In another bowl, combine the wet ingredients: melted butter, buttermilk, eggs, and vanilla extract. Whisk until well combined. The buttermilk adds moisture and a slight tang, while the butter provides richness.

Pour the wet ingredients into the dry ingredients. Using a rubber spatula, gently fold the mixture together until just combined. Be careful not to overmix; a few lumps are okay. Overmixing can lead to tough muffins.

Gently fold in the blueberries, taking care not to break them. This will ensure that the blueberries are evenly distributed throughout the batter.

Line a muffin tin with paper liners or grease with non-stick spray. This prevents the muffins from sticking and makes for easy removal.

Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full. This allows room for the muffins to rise without overflowing.

Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Baking time may vary depending on your oven.

Once baked, remove the muffins from the oven and let them cool in the pan for 5 minutes before transferring them to a cooling rack. This helps them set and makes them easier to remove.