Preheat the oven to 350°F. Line a 9x13 with foil or parchment paper and spray with cooking spray, set aside. In a medium-sized bowl stir together the flour, pumpkin spice, baking soda, and salt, set aside.
In a medium-sized bowl or the body of a stand mixer with the paddle attachment cream together the dark brown sugar, butter, and granulated sugar until smooth, 2 minutes. Add the egg and stir until combined. Add the pumpkin and vanilla, stir until smooth.
Add the dry mix to the wet and mix until combined with no dry patches. Add the chocolate chips and stir them in.
Press the dough into the prepared baking side. I find it easier to spread with slightly moistened hands. Bake for 40-45 minutes until a toothpick inserted into the center comes out clean. Let cool completely, cut, and serve.
To Store: Store any leftovers in an airtight container on the counter for up to 3 days. If you refrigerate them, they’ll last for about 5 days.
To Freeze: Once your blondies have cooled completely, you can wrap them in plastic wrap or foil and place in a freeze-safe container. Store in the freezer for up to 3 months. Let thaw at room temperature for a few hours when ready to eat.
I like to line my baking dish with parchment paper before pouring in the batter. I usually leave enough parchment hanging over the edges of the pan so that I can easily lift the blondies out once baked. It makes both removal and clean up a lot easier.
After removing from the oven, let the bars cool for about 20 minutes before cutting into squares. They get a bit crumbly if you slice them while warm.
Make sure to use pumpkin puree, NOT pumpkin pie filling (which has already been sweetened and spiced).