In a large bowl, whisk together flour, baking powder, sugar, salt, cinnamon.
Add the grated frozen butter into the flour mixture, and work it in with your fingertips until it resembles wet sand, see post above for visuals. You can also use a pastry cutter, but I find hands easier!
In a separate bowl mix together heavy cream, egg and vanilla. Add the wet ingredients and the chopped dates to the flour, and mix together until combined with a spatula or fork. You can knead the dough a couple times with your hands, but don't overwork the dough, a shaggy dough is perfect.
Line an 8 inch circle cake pan with parchment paper overhanging the sides. Pat the dough in to form an 8 inch circle, then turn it out onto a lightly floured surface. Alternately, pat the dough into an 8 inch circle. Cut the circle into 8 wedges, and place onto a parchment paper lined baking sheet. Place the sheet with the dough on it into the fridge to rest for 15 minutes.
While dough is resting, heat oven to 400 F (200C). Take scones out of the fridge, and brush the top of each with a little heavy cream, and optionally sprinkle with some coarse sugar. Bake for 20-25 minutes, until edges and top are a light golden brown.
Serve warm, either plain or with some cream and/or jam.