Follow these simple steps to make the most incredible blueberry muffins:

1. Preheat Oven: Set the oven to 375°F (190°C) and line a muffin tin with paper liners.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, granulated sugar, baking powder, baking soda, and salt.
3. Combine Wet Ingredients: In another bowl, mix the melted butter, buttermilk, eggs, and vanilla extract. Whisk until combined.
4. Combine Mixtures: Pour the wet ingredients into the dry ingredients. Stir gently until just combined, being careful not to overmix.
5. Fold in Blueberries: Gently fold the blueberries into the batter, ensuring they are evenly distributed.
6. Fill Muffin Tin: Spoon the batter into the lined muffin cups, filling each about 2/3 full.
7. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes or until a toothpick inserted comes out clean.
8. Cool: Remove from the oven and let the muffins cool in the tin for about 10 minutes. Transfer them to a wire rack to cool completely.
9. Enjoy: Serve warm, or store in an airtight container if you have leftovers (though they may not last long!).