Preheat oven to 400 degrees. Line a large baking sheet with parchment paper or a silicone baking mat.
In a large bowl, whisk the flour, baking powder, cinnamon, and salt together.
Grate the frozen butter using a box grater, it will take only a minute to do so.
Add the grated butter into the flour mixture and combine it with a pastry cutter, a fork, or your fingers until the mixture resembles coarse crumbs, about the size of peas.
In a small bowl, whisk the 1/2 cup cream, light brown sugar, egg, and vanilla extract together.
Slowly drizzle it over the flour mixture and then combine the mixture together using a wooden spoon or a rubber spatula until everything is combined.
Add in the chocolate chips.
With floured hands, work the dough into a ball as best you can and transfer to a floured surface. The dough will be sticky. Press into a 8-inch circle and then cut into 8 equal wedges with a knife.
Place scones at least 2 inches apart on the prepared baking sheet.
Brush scones with remaining heavy cream.
Bake for 20-25 minutes or until lightly golden and cooked through. Remove from the oven and allow to cool on the pan for a few minutes. Then remove to wire rack to cool completely.
Once the scones are cooled, prepare the glaze by whisking the powdered sugar, heavy cream, and vanilla in a small bowl. Drizzle over scones, and let sit a few minutes until the glaze is set. If your glaze is too thick, add a bit more glaze, or if it’s too thin, add a bit more powdered sugar.