Preheat oven 400’ grease 12 muffin cups, set aside
Add all the dry ingredients to a medium sized bowl and stir together; set aside.
Whisk together buttermilk, sour cream, eggs and 3 Tbs butter. Add to flour mixture. Stir until just moistened. Do not over mix; batter should still be lumpy.
Gently fold in the blueberries. Spoon batter into prepared muffin cups. Filling each three-fourths full; bake 18 minutes or until golden brown.
Brush with remaining butter and sprinkle with Turbinado Sugar aka Sugar in the Raw.
Cool in muffin cups on a wire rack for 5 minutes. Make sure to let the muffins rest the 5 minutes so they don’t fall apart but do not wait too long that they become soggy.
