Preheat your oven to 375°F (190°C) and line a muffin tin with paper liners.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt until well combined.
In a separate microwave-safe bowl, melt the butter. Allow it to cool slightly before whisking in the eggs, milk, and vanilla extract.
Pour the wet ingredients into the dry ingredients, and gently mix until just combined. Be careful not to overmix, as this can result in dense muffins.
Gently fold in the fresh blueberries, ensuring that they are evenly distributed throughout the batter.
Using a spoon or an ice cream scoop, divide the batter equally among the prepared muffin cups. Fill each cup about three-quarters full.
Optional: For an extra touch of sweetness and texture, sprinkle some granulated sugar on top of each muffin.
Place the muffin tin in the preheated oven and bake for 18-20 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean.
Once baked, remove the muffins from the oven and allow them to cool in the tin for a few minutes. Then transfer them to a wire rack to cool completely.
Serve the homemade blueberry muffins warm or at room temperature. They are best enjoyed on the day they are made, but can be stored in an airtight container for up to three days.