In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt.

Add the cold, cubed butter to the dry ingredients. Using a pastry cutter or your fingers, work the butter into the mixture until it resembles coarse crumbs.

In a separate bowl, whisk together the buttermilk, egg, and vanilla extract.

Pour the wet ingredients into the dry ingredients and gently mix until just combined. Be careful not to overwork the dough.

Turn the dough out onto a lightly floured surface and gently press it together to form a round disk about 1 inch thick.

Using a sharp knife or dough cutter, cut the disk into 8 equal wedges.

Place the wedges on the prepared baking sheet, leaving space between each one.

Bake in the preheated oven for 15-18 minutes, or until the scones are golden brown and a toothpick inserted into the center comes out clean.

Remove from the oven and let cool slightly on a wire rack before serving.