1cuppowdered or course sugar(for coating, optional)
Preheat oven to 375°.
With paper liners, line 18 muffin pan cups, or grease them well. Sift flour with baking powder and salt. Set aside. In large bowl, with electric mixer at high speed, beat butter with sugar, eggs and vanilla until light and fluffy. At low speed, beat in flour mixture alternately with milk, beginning and ending with flour mixture. Beat just until smooth. Stir in blueberries.
Bake at 375° for 20-25 minutes, or until golden brown. Remove muffins to wire rack; let cool slightly. Serve warm or cold, sprinkled with powdered or course sugar (optional).