Preheat oven to 400°F, position oven rack in the center. Spray a muffin tin with non stick spray including the top of the pan. Line with muffin paper liners (due to blueberries, these muffins can stick to the pan)
In a stand-alone mixer fitted with a paddle attachment, cream butter (if you don't have a stand mixer, you can use an electric hand mixer). With the mixer on low, gradually add 1 cup granulated sugar. Scrape the sides down then beat on medium speed until light and fluffy, about 5-7 minutes.
Gradually add the eggs, one at a time, and beat until blended. Add the vanilla extract. Beat for a few minutes on medium until light and fluffy.
Spoon and level 1¼ cups of bread flour (substitute all-purpose flour) and ¾ cup cake flour (substitute pastry flour), 2 teaspoons baking power and ½ teaspoon of kosher salt. Sift together over a mixing bowl and whisk to combine all the ingredients.
Add the dry and wet ingredients to the creamed mixture alternating between flour and milk, starting and ending with flour and scraping down the sides as you go. Beat on low just to combined. Don't over mix (or you will have tough chewy muffins)
Remove the mixing bowl from the stand-alone mixer and scrape off any batter from the paddle attachment.
In a small bowl, mash ½ cup of blueberries. Fold into the batter with a spatula. In a separate bowl, coat and toss whole blueberries with 2 Tablespoons of flour and fold into the batter.
Generously fill each muffin cup to the top. Sprinkle a teaspoon or so of granulated sugar over each muffin.
Note: I used 1 teaspoon of sugar as a measuring unit, but in the original recipe, enough sugar was spread over the top to completely cover.
Bake at 400°F for 5 minutes. Lower temperature to 375 and bake for another 20. Muffins may need another five minutes for a total of 30 minutes. Tops should be lightly golden.
Insert a toothpick to test for doneness. If it comes out clean, remove the muffins from the oven and allow to cool in the pan for about 30 minutes.
Remove and finish cooling on wire rack.
For me the best way to eat these is right out of the oven with some good quality butter. Enjoy!