Preheat your oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving some overhang on the sides for easy removal. Lightly grease the parchment paper.
In a large mixing bowl, whisk together the melted butter, pumpkin puree, brown sugar, and granulated sugar until smooth and well combined.
Add the egg and vanilla extract, and whisk until fully incorporated.
In a separate bowl, whisk together the flour, cinnamon, pumpkin pie spice, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing with a spatula until just combined. Be careful not to overmix, as this can make the bars tough.
Gently fold in the chocolate chips, making sure they are evenly distributed throughout the batter.
Pour the batter into the prepared baking pan, spreading it out evenly with a spatula. If desired, sprinkle a few extra chocolate chips on top for a decorative touch.
Bake in the preheated oven for 25-30 minutes, or until the edges are set and a toothpick inserted into the center comes out with just a few moist crumbs. The bars should still be slightly fudgy in the center
Allow the bars to cool completely in the pan on a wire rack. Once cool, use the parchment paper overhang to lift the bars out of the pan. Cut into squares and enjoy!
