Preheat your oven to 400°F (200°C).
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt.
Add the cold, cubed unsalted butter to the dry mixture and cut it in until it resembles coarse crumbs.
In a separate bowl, mix the buttermilk and vanilla extract, then pour into the flour mixture and stir gently until combined.
Turn the dough onto a floured surface, knead gently, and pat into a circle about 1 inch thick.
Cut out rounds using a floured cookie cutter and place them on a baking sheet lined with parchment paper.
Bake for 15-20 minutes or until golden brown on top.
Let cool on a wire rack for a few minutes before serving warm with clotted cream and jam.
