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).
1/2 cup unsalted butter
In a medium bowl, combine flour, pumpkin pie spice*, baking soda and salt. Whisk to combine, and set aside.
1 1/2 cups all-purpose flour, 2 teaspoons pumpkin pie spice*, 1 teaspoon baking soda, 1/4 teaspoon salt
In a large bowl, combine melted butter, brown sugar and corn syrup. Whisk to combine.
1/2 cup light brown sugar, 1/4 cup Karo® Corn Syrup
Add pumpkin and vanilla, and whisk again to combine.
1/3 cup canned pumpkin, 1 teaspoon pure vanilla extract
Add the flour mixture to the pumpkin mixture and stir until just combined. Add chocolate chips and stir again until just combined.
1/2 cup chocolate chips
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!
Notes
*If you don't have pumpkin pie spice, substitute the following:
Make sure all your canned pumpkin is room temperature before you start - if you had some leftover in the fridge that you're going to be using, just let it set out for 15 minutes to come to room temperature. The texture changes slightly when it's chilled and could be difficult to combine, so make your life easier and start with room temperature canned pumpkin.
Use a large sturdy whisk for mixing the wet ingredients, then switch over to a wooden spoon or spatula for the rest. The mixture will get too thick for the whisk and get stuck in it.
Use your favorite kind of chocolate chips: semi-sweet, milk chocolate, dark chocolate - whatever you like! You can even use mini chocolate chips if you want.
Cover your bowl of dough with plastic wrap and place in the fridge for at least30 minutes, but I recommend 1 hour. Chilling the dough is non-negotiable because it's pretty sticky and needs that time to firm up before you bake them.
Press down on the top of each cookie (and add a few more chocolate chips to the top, if you want, for presentation's sake) to flatten them a bit - they won't spread much as they bake. They will be a bit puffy when they first come out of the oven and then deflate a bit and crinkle on top as they cool.
I find the best results when you portion out 6 cookies on each baking sheet, but only work on sheet at a time. Scoop out six cookies from your chilled dough, roll them into balls, flatten the tops, stick the pan in the oven and put the bowl back in the fridge. Keeping the dough chilled until you're ready for it will result in evenly baked cookies, and they'll be more uniform in size and spread.