Preheat oven to 400°.

In a food processor, pulse together flour, ¼ cup sugar, baking powder, and salt. Add butter and pulse until pea-size pieces form.

In a small bowl, whisk together buttermilk and egg yolk.

Slowly pour buttermilk mixture through feed tube into processor, pulsing until dough just comes together.

Transfer dough to a lightly floured work surface and sprinkle raspberries on top.

Knead three time to fold in raspberries (loose pieces of dough okay).

Gather and pat dough into a 1-inch thick square and cut or pull apart into 2-inch pieces.

Place pieces, about 2 inches apart, on two parchment-lined baking sheets and sprinkle tops with 1 Tbsp sugar.

Bake until golden brown, 15 to 18 minutes, rotating sheets halfway through.

Let scones cool slightly on wire racks.

Serve warm or at room temperature.

Can store in an airtight container, up to one day.