Beat butter and sugar until light and fluffy.  Add eggs in one at a time and beat until incorporated. Add sour cream and vanilla and continue to beat.

Add flour, baking powder and salt and beat.  

Fold in blueberries.  

Using an ice cream scoop with release, fill a lined muffin tin with batter to the top.  Sprinkle with turbinado sugar.  Bake at 350 for 20-24 minutes until tops are puffed and slightly golden and toothpick comes out clean.