Preheat the oven to 425 degrees. Line a muffin pan with liners and spray the tops of the pan with cooking spray.
In a medium bowl, whisk together the flour, baking powder, baking soda and salt.
In the bowl of a stand mixer, combine the butter and sugar and beat on medium speed for 1-2 minutes. Add in the egg and mix until combined.
Alternate between the buttermilk and flour mixture until combined, then add in the vanilla.
Fold in the blueberries by hand.
Fill each muffin cavity to almost full. Sprinkle sanding sugar on top of each muffin.
Bake for 5 minutes and then without opening the oven, reduce the temperature to 350 degrees and bake for an additional 12-15 minutes or until a toothpick inserted in the center comes out clean.
Remove from the oven and let cool in the muffin pan for a few minutes before transferring to a wire rack to cool completely.
*If you don't have buttermilk, you can make it by adding 1 tablespoon white vinegar to 1 cup milk, or use any other type of milk you have. The less fat in the milk, the more dry the muffin will be.*If using frozen blueberries, toss in 1-2 tablespoon of flour before mixing into the batter.
Recipes on Cookaholic Wife are for information purposes only. Nutritional Data provided has not been evaluated by a nutritionist.