1. Preheat oven to 425 degrees F.
2. In a food processor, blend together the flour, sugar, baking powder and baking soda.
3. Pulse in the cold butter. Do not over incorporate the butter into the flour. Similar to making a flaky pastry, small pieces of butter should be visible in the flour.
4. Transfer this mixture from the food processor into a large mixing bowl. Toss in the frozen blueberries.
5. Make a well in the center. Pour in the milk and vanilla extract.
6. Working very quickly with a wooden spoon, fold the dry mixture through the buttermilk, only until the flour disappears, then stop immediately.
7. Drop the sticky dough onto a well floured counter top or bread board. Sprinkle the top of the dough with additional flour as well as flouring your hands to handle the dough. I don't even use a rolling pin for these scones, the dough is soft enough to pat it out gently with floured hands to a thickness of about 1 & 1/2 inches.
8. Using a sharp 2 inch biscuit cutter cut the scones out an place them about 2 inches apart on a parchment paper lined baking sheet. I recommend aluminum baking sheets because they tolerate the higher oven temperature without burning the bottom of the scones.Alternatively, instead of using a biscuit cutter, just form the dough into a round and cut it in wedges like a pie. This is often my preferred method because you don't have to re-roll the scrap dough.
9. If you like you can brush the tops with an egg wash made from whisking together the egg and milk.
10. Bake in the preheated oven for about 10 minutes then reduce the heat to 375 degrees F and bake for an additional 10-15 minutes or until the tops of the scones are evenly golden brown. Delicious served warm with Honey Butter.

To prepare the Honey Butter

1. Honey butter is simply honey beaten into plain butter in a 2 to 1 ratio of butter to honey.
2. Beat together with an electric mixer until smooth and fluffy.