Preheat oven to 350F. Line 9x 13 cookie sheet with parchment paper and set aside.
In a large bowl, sift all dry ingredients
Using a pastry knife cut the butter into the flour and mix until pea-sized crumbs form.
Gently fold in blueberries
Gently fold in Greek yogurt and optional egg and vanilla extract mixture until well incorporated
Transfer dough onto the cookie sheet and press into a rectangle about 1 inch thick
Score dough with a knife to precut the scones into 12 pieces
Bake for 20-25 min or until golden brown
Once baked, score the scones with a knife to fully cut into 12 pieces