Preheat oven to 400-degrees Fahrenheit (205 degrees Celsius)
Add 2 cups of flour, sugar, baking powder, and salt in a large bowl.
In a small bowl, whisk together buttermilk, egg yolk, and vanilla extract.
Add the buttermilk mixture to the flour mixture and stir until just combined.
Add the blueberries and melted butter to the dough and stir gently to combine.
Line a baking sheet with parchment paper and dust with additional flour.
Turn the dough out onto the parchment paper and sprinkle with additional flour.
Gently pat the dough into an (approximate) 8" disc.
Flour a knife or bench scraper and divide the dough disc into 8 equal pieces.
Bake the scones in a preheated oven for 20-25 minutes, or until the scones are a deep golden brown and when a toothpick inserted into the center comes out clean.
Cool the scones completely on a wire rack.