Preheat oven to 350 degrees F and line a muffin tin with cupcake liners (or spray the cups generously cooking spray).
Using a stand mixer fitted with the paddle attachment (or a large mixing bowl with a hand mixer), combine the butter and sugar and beat until combined. Add the lemon zest, egg and sour cream and beat on medium-low speed until creamy.
In a separate bowl, combine the flour, baking powder, baking soda and salt. Mix well. Gradually add to the butter mixture and beat on medium-low speed until just combined. Gently fold in the blueberries.
Divide the batter between the prepared muffins cups. The batter will be thick and the cups will be full. Sprinkle the sugar evenly over the tops. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the centers comes out clean. Serve warm!
Notes
The batter will be nice and thick (very unlike cake/cupcake batter).
Fill all 12 muffin cups so they are heaping.
Feel free to replace fresh blueberries with frozen, but if you do this reduce the amount used by 1/2 cup.
Replace the turbinado sugar (for topping) with granulated sugar if you must, but that extra little sugar crunch is glorious!