Preheat the oven to 375F degrees. Line a muffin pan with muffin papers.
Whisk together the flour, baking powder, baking soda & salt in a medium bowl.
In a large bowl beat the butter and sugar until fluffy (about 2 minutes).
Beat in the eggs 1 at a time followed by the vanilla extract.
Using a large rubber spatula, stir in the sour cream followed by about 1/2 of the flour mixture.
Then stir in the milk, followed by the rest of the flour mixture. The batter should be thick.
Carefully fold in the blueberries.
Spoon the batter into the prepared muffin pan, filling each muffin cavity to the top (about 1/4 - 1/3 cup batter). Optionally, sprinkle each muffin with a little coarse sugar.
Bake in the preheated oven for 16-20 minutes or until the tops are golden and an inserted toothpick comes out clean (except for blueberry juice).