Melt butter in your preferred manner (either in the microwave or in a small saucepan on the stove), and let cool slightly (about 10 minutes).
In a medium bowl, combine flour, pumpkin pie spice*, baking soda and salt. Whisk to combine, and set aside.
In a large bowl, combine melted butter, brown sugar and corn syrup. Whisk to combine.
Add pumpkin and vanilla, and whisk again to combine.
Add the flour mixture to the pumpkin mixture and stir until just combined. Add chocolate chips and stir again until just combined.
Cover bowl and place in the fridge to chill for at least 30 minutes, preferably 1 hour.
Preheat oven to 350°F and line two baking sheets with nonstick silicon mats or parchment paper. Set aside.
Use a medium cookie scoop to portion out dough onto first prepared baking sheets (no more than 6 on a sheet at a time), roll into balls, flatten the tops a bit with your hand or the bottom of a glass, and bake for 10 minutes. Let cool for 10-15 minutes on baking sheet, then move to wire rack to cool completely.
Put the bowl of dough back in the fridge between each batch to ensure it stays chilled as long as possible - this will make it easier to work with and more uniform when they bake. Enjoy!