Combine all dry ingredients. Add in the butter until it is in pea-sized pieces.
Mix in buttermilk, vanilla, and pumpkin.
Fold the blueberries into the dough, but try not to break them.
On a floured surface, knead the dough for 1 1/2 minutes until firm and moist. Roll the dough into a long rectangle and cut in half width wise, so the dough is in two squares. Cut each square twice from corner to corner to make 8 triangular scones.
Place the scones on a baking sheet with parchment paper and bake for about 20-22 minutes, or until golden brown.
For the blueberry glaze:
Juice the blueberries or push them through a strainer to separate the blueberry juice from the skin. Try to remove as much skin as you can - the more skin, the thicker the glaze will be.
Combine the blueberry juice with the powdered sugar and milk. Wait until the scones are completely cooled before drizzling the glaze on top.