Heat oven to 425 degrees. Chop the butter into pieces about ½ tablespoon big. Then in either a food processor or a blender, combine the sugar, flour, and butter. Use the pulse setting to blend until the mixture is a consistent crumbly texture.

Beat the egg. Pour the flour mixture into a bowl. Add the egg and the buttermilk and fold together. Add more buttermilk if all of the flour isn't being mixed into the dough. I used ½ cup of buttermilk, plus a couple tablespoons.

Fold in the blueberries. Be gentle. You don't want to crush the blueberries.

Divide the mixture into a scone pan, filling each space until it is nearly full. If you don't have a scone pan, use between ¼ and ⅓ cup of the dough to form triangles and space them out on a baking sheet.

Bake the scones for 12-14 minutes, or until a toothpick inserted into the middle comes out clean. Remove the scones from the oven, use a knife to remove them from the scone pan, and place them on a cooling rack. (Side note: While a scone pan might seem like an oddly specific thing to own, it is really useful. You can use it to make perfectly triangular shaped desserts and treats.)

In a small bowl, mix together the powdered sugar, vanilla, and milk. Start by adding about ½ teaspoon of the milk and vanilla. Slowly add more if necessary. The goal is to create a thin glaze to drizzle over the scones.

Once the scones have cooled, drizzle the vanilla glaze over. Serve right away, or cover and save for later.