01 - Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper, ensuring full coverage.
02 - In a large mixing bowl, thoroughly whisk together the all-purpose flour, granulated sugar, baking powder, salt, and ground cinnamon until uniformly distributed.
03 - Add the cold, cubed unsalted butter to the dry ingredients. Utilize a pastry blender or your fingertips to incorporate the butter until the mixture achieves the consistency of coarse crumbs.
04 - In a separate bowl, whisk together the heavy cream, large egg, and vanilla extract until well blended. Pour this wet mixture into the dry ingredients and gently combine until just incorporated, avoiding overmixing.
05 - In a small bowl, combine the packed brown sugar and ground cinnamon for the filling until evenly mixed.
06 - Transfer the dough to a lightly floured surface. Gently pat or roll the dough into a rectangle measuring approximately 10 by 6 inches.
07 - Evenly sprinkle the prepared cinnamon-brown sugar mixture over the entire surface of the dough rectangle.
08 - Fold the dough into thirds, similar to folding a letter. Gently shape the folded dough into a circle approximately 7 inches in diameter and about 1 inch thick.
09 - Cut the dough circle into 8 equal wedges. Carefully place the wedges onto the prepared baking sheet, ensuring adequate spacing.
10 - Brush the tops of the scones with any additional heavy cream. Generously sprinkle the granulated sugar over the cream-brushed tops to create a crisp topping.
11 - Bake for 16 to 18 minutes, or until the scones achieve a golden-brown hue. Allow to cool slightly on the baking sheet before serving.