Preheat oven to 400 degrees F. Generously spray 12 count muffin tin with nonstick cooking spray.
In a large bowl combine flours, granulated sugar, baking powder, baking soda and salt; stir until all ingredients are well blended.
In another bowl, whisk together the buttermilk, butter, eggs and vanilla. Make a well in the middle of the dry ingredients and pour in the liquid mixture; then add the blueberries. Gently fold ingredients just until moist; do not overmix.
Spoon batter evenly into muffin tin. Cups will be close to full. Sprinkle the top of each muffin with about 1 teaspoon turbinado sugar. Bake for 18 to 22 minutes.