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

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

In a separate bowl, mix the melted butter, egg, and milk until well combined.

Pour the wet ingredients into the dry ingredients and stir gently until just combined.

Fold in the fresh blueberries carefully to avoid crushing them.

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

Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted comes out clean.

Allow muffins to cool in the pan for 5 minutes before transferring them to a wire rack.

Store any leftovers in an airtight container at room temperature.

Enjoy your delicious homemade blueberry muffins warm or at room temperature!