In a small bowl, add the melted butter and sugars and whisk until the sugars have dissolved. Stir in the vanilla extract and pumpkin puree. Set Aside.
Whisk together the flour, baking soda, baking powder, cinnamon, pumpkin pie spice, nutmeg, and salt in a large bowl.
Add the wet ingredients to the dry, stirring with a silicone spatula or wooden spoon until the mixture is evenly incorporated. Gently fold in the chocolate chips.
Cover the bowl with plastic wrap and set it in the refrigerator. Chill the dough for at least 1 hour or up to 3 days.
Once chilled, preheat the oven to 350F and line an 8x8 pan with foil. Press the dough evenly into the pan and add some extra chocolate chips to the top. Bake for 30-35 minutes or until the edges appear lightly browned. Allow the bars to cool for at least 30 minutes before lifting the foil out and cutting into bars.