1Preheat oven to 375° F. Line 12 muffin cups with paper liners or coat with coconut oil.
2In a large bowl, whisk together the flour, baking powder, and salt.
3In a medium bowl, whisk together the sugar, butter, milk, and eggs; add to the flour mixture and stir to combine.
4Fold in the blueberries (do not overmix).
5Divide the batter among the prepared muffin cups and sprinkle with the turbinado sugar, if desired.
6Bake until a toothpick inserted in the center of a muffin comes out clean, 20 to 25 minutes.
7Let cool in the pan for 5 minutes. Transfer to a wire rack to cool completely or serve warm.