Preheat oven to 400°f/200°C. Line a 6 cup jumbo muffin pan with high walled paper cups or grease and flour. You can also use a 12 cup muffin pan.
In a medium bowl combine all purpose flour, baking powder, baking soda and salt. Mix together well and set aside.
In a large bowl cream together unsalted butter and sugar until light and fluffy. If your butter is very soft you can do this by hand. You can also use an electric mixer. Add eggs, one at a time, beating well after each addition. Add sour cream (or yogurt if using), oil, milk and vanilla. Mix until well combined.
Add about ¼ of the dry ingredients and mix until almost combined. Add the remaining dry mixture in 2 or 3 more stages. Do not mix all the flour in yet.
Reserve 15-20 blueberries for decorating on top (this is optional) and set aside. Add the remaining blueberries to the batter and fold until everything is incorporated. Do not over mix.
Divide the batter among the 6 (or 12 if using) baking cups. There should be enough batter to make them very full (they will exceed the muffin cups). They will grow but they should not over flow. Decorate each muffin with some of the reserved blueberries, if you are doing this. Sprinkle each one with Turbinado sugar. Bake for 25-30 minutes for jumbo muffins, 20-22 minutes for regular muffins. Test with toothpick to see if batter comes out clean.
Cool muffins in the pan on a wire rack for 10 minutes before removing. Cool completely or serve warm.