Line a baking sheet with parchment paper. Set aside.
Grate the frozen butter using a box grater. Return the grated butter to the freezer to stay cold as you prepare the rest of the ingredients.
Whisk flour, baking powder, cinnamon, and salt together in a large bowl. Add the grated butter to the flour mixture and combine with your fingertips, two forks, or a pastry cutter until the mixture you have pea sized crumbs.
Stir in white chocolate chips until just combined. Whisk to combine the heavy cream, egg yolk, sugars, and vanilla in a small bowl. Pour the wet ingredients over the flour mixture and stir until slightly til combined then stir the cranberries in until just combined. Do not overmix. Dough shouldn't be too dry and should be somewhat sticky, but not too sticky. If dry there are some dry spots, add a bit more heavy cream and if it's too sticky (sticking to your hands a lot), add a little more flour.
Turn the dough out onto a lightly floured surface. Lightly flour your hands. Shape the dough into a circle about 1-1 1/2 inches thick. Aim for a circle between 6 and 8 inches. Use a sharp knife to slice the dough into 8 triangles.
Place scones at least 2 inches apart on prepared baking sheet. Sprinkle tops of scones generously with coarse sugar, if desired. Refrigerate scones 15 minutes.
Preheat oven to 400 F. Bake scones for 17-20 minutes or until golden brown around the edges and lightly browned on top.
Allow scones to cool. Drizzle with melted white chocolate, if desired.