Preheat oven to 375F (190C) and line a baking sheet with parchment paper (alternatively bake scones directly on ungreased baking sheet). Set aside.
Add flour, sugar, baking powder and salt in the basin of a food processor fitted with a chopping/mixing blade and pulse briefly to combine.
Cut butter into 12 pieces and scatter over the top of the flour mixture. Pulse again until butter is cut into pebble-sized pieces into the flour.
Measure out cold cream and add vanilla extract. Stir gently to combine, then pour mixture evenly over the surface of the flour/butter. Pulse again until mixture begins to clump together (it may still be a bit crumbly, this is fine, and better than overworking the dough!).
Transfer to a clean, lightly floured surface and scatter frozen raspberries over the top. Work dough and raspberries together into a cohesive rectangle.
Use a knife to cut the dough in half and place the first half directly over the second. Press down to work the dough back into a cohesive, rectangular square (we are “laminating” the dough to help encourage light flaky layers, much like with biscuits). Repeat this process 3-4 more times until you have a rectangle that is approximately 8x5” (20x12cm).
Using a sharp knife, cut into six even squares, pressing straight down with the knife and never sawing (which can cause lopsided scones).
Space scones 1-2” apart on baking sheet and, if desired, lightly brush tops with additional heavy cream and sprinkle with coarse sugar.
Transfer to oven and bake for 15-17 minutes or until scones are cooked through and light golden brown on the edges. Allow to cool on baking sheet before enjoying!
The colder your butter the better, and the lighter more tender, and flakier your scones will be! I like to place mine in the freezer 15-30 minutes before I begin.
If you do not have a food processor you can either grate the butter into the flour mixture or cut it in with a pastry cutter instead. After combining it with the flour, stir in the heavy cream and vanilla extract. The dough will seem dry, but it should ultimately come together but requires a bit more manual work (and you do run the risk of over-handling the dough and making it too warm).
Scones are best enjoyed fresh and warm! If you have any leftovers they will keep for 24-48 hours in an airtight container at room temperature. Leftover raspberry scones may also be frozen for several months.