Pre-heat the oven to 375°F.
In a medium bowl, cream the butter and 1-¼ cups sugar until light.
Add the eggs, one at a time, beating well after each addition; add vanilla; stir to combine.
In a separate medium bowl, sift together the flour, salt and baking powder; add to the creamed mixture, a little at a time, while alternating with the milk; stir after each addition of the creamed mixture and the milk.
Using a medium bowl, toss the berries in flour before adding which will keep them from sinking to the base of the muffin tin.
Crush ½ cup blueberries with a fork; mix into the batter; fold in the remaining whole berries.
Line a 12 cup standard muffin tin with cupcake liners and fill with batter.
Sprinkle the 3 teaspoons sugar over the tops of the muffins.
Place in the pre-heated oven and bake for about 30 to 35 minutes.
Remove muffins from the oven; remove muffins from the tin and cool, on a wire rack, at least 30 minutes.
Store, uncovered, to ensure the muffins are still moist on day two.
