Preheat the oven to 350 degrees. Line a 9x13 inch baking dish with foil and spray with nonstick spray, set aside.
Add the butter to a large skillet over medium heat. Stir occasionally for about 3-4 minutes until the butter begins to foam and deepen to a golden brown color. Remove the pan from the heat and pour the butter into a separate heat proof bowl to cool for 5 minutes.
Meanwhile, in a large bowl whisk together the flour, pumpkin pie spice, baking powder, cinnamon and salt until combined.
To the melted butter add the egg, brown sugar, pumpkin puree, and vanilla extract and whisk until combined.
Pour the butter mixture into the flour mixture and use a spatula to stir just until combined. Then, fold in the chocolate chips.
Pour the batter into the prepared pan and use your hands or a spatula to spread the batter out evenly (it will be very thick) bake for 25-30 minutes until the top is golden brown and the batter is set in the center.
Allow the bars to cool before removing from the pan and slicing as desired.