Soak the raisins in orange juice for about 10 minutes. Drain before using.
In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and cinnamon if using.
Grate the frozen butter using a box grater. Add it to the flour mixture and gently toss until the mixture resembles coarse crumbs.
Pour the buttermilk and vanilla into the dry ingredients. Mix gently until the dough just comes together.
Fold in the soaked raisins.
Turn the dough onto a lightly floured surface.
Press into an 8 inch disc about 1 inch thick.
Cut the dough in half and stack one half on top of the other.
Press again into an 8 inch disc about 1 inch thick.
Cut the dough into 8 wedges using a sharp knife or bench scraper.
Place the scones on a parchment lined baking sheet and refrigerate for 30–45 minutes.
Preheat oven to 400°F.
Brush the tops with egg/heavy cream wash.
Bake for 18–22 minutes, until golden brown and cooked through. (If the tops darken too quickly, loosely cover with foil for the final minutes.)
Let the scones cool slightly on a wire rack before serving.