Cream the butter and 1 � cups sugar until light. Add the eggs, one at a time, beating well after each addition. Add vanilla extract.
Sift together the flour, salt and baking powder, and add to the creamed mixture alternately with the milk.
Crush � cup blueberries with a fork, and mix into the batter. Fold in the remaining whole blueberries.
Line a 12 cup standard muffin tin with cupcake liners, and fill with batter. Sprinkle the 3 teaspoons of sugar over the tops of the muffins, and bake for about 30-35 minutes.
Remove the blueberry muffins from the tin and let cool.