1. Preheat oven to 350 degrees. Line bottom and sides of a 9-by-13-inch baking pan with parchment, leaving an overhang on all sides. Grease with nonstick cooking spray.
2. In the bowl of a stand mixer fitted with the paddle attachment, cream butter and sugars on medium-high speed until smooth; beat in egg and vanilla until combined. Beat in pumpkin puree.
3. Add in the flour, pumpkin pie spice, cinnamon, baking soda, and salt.
4. Mix until just combined. Fold in shaved chocolate.
5. Spread batter evenly in prepared pan. Bake until edges begin to pull away from sides of pan and a toothpick inserted in center comes out with just a few moist crumbs attached, 35 to 40 minutes. Cool completely in pan.

Storage: Store the pumpkin blondies in a single layer inside an airtight container for up to three days.