Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper.
Whisk together the flour, sugar, baking powder, baking soda, salt, pumpkin pie spice, and cinnamon in a large mixing bowl until evenly combined.
Add the grated cold butter and gently work it into the flour mixture using a pastry cutter or your fingertips until the mixture resembles coarse crumbs with small pieces of butter throughout.
In a separate bowl, whisk together the pumpkin purée, egg, heavy cream, and vanilla until smooth.
Pour the wet ingredients into the dry ingredients and stir gently just until the dough begins to come together. Fold in the chocolate chips, taking care not to overmix.
Transfer the dough onto a lightly floured surface and gently press it into an 8-inch round about 1 inch thick. Cut the round into 8 equal wedges.
Arrange the wedges on the prepared baking sheet, leaving space between each one. Refrigerate the shaped scones for about 20 minutes to help them bake up tall and flaky.
Brush the tops with the egg wash and sprinkle with the cinnamon sugar mixture if using.
Bake until the tops are lightly golden and the centers are set, about 18 to 20 minutes.
Let the scones cool on the baking sheet for 5 minutes before transferring them to a wire rack. Enjoy warm or at room temperature.