Make the caramel sauce according to the recipe instructions.
Spray a 9×9-inch baking dish with cooking spray and preheat the oven to 350℉.
To make the blondies, combine flour, cinnamon, nutmeg, baking soda, and salt.
Cream together the butter and brown sugar until very light and fluffy, about 2 minutes. Add the egg and vanilla extract.
Add the pumpkin purée and the reserved flour mixture. Mix until just combined.
Transfer half of the batter to the prepared pan and bake for 10 minutes.
Remove the pan from the oven and pour over 1 cup of the caramel sauce.
Cover the caramel with the remaining batter.
Return the pan to the oven and bake for an additional 30 minutes. A toothpick inserted in the center should come out clean. Let the blondies cool in the pan for 1 hour before cutting.
Serve with a drizzle of the remaining caramel sauce.