Preheat your oven to 400°F.
Whisk together the flour, cornstarch, salt, pumpkin pie spice and baking powder.
In a separate larger bowl, cream together the butter and sugar until the color changes and it is light and fluffy. This should take about 2-3 minutes. Then add the pumpkin and beat until fluffy. This should take another 2-3 minutes. Make sure to beat on low speed so the emulsified mixture doesn't break.
Fold in the dry ingredients until well combined, then add in your chocolate chips.
Chill the dough for 30 minutes in the fridge while you preheat the oven to 400°F.
Once the dough is chilled, form it into 8 balls that are 75g each. Place on a parchment lined baking sheet and bake at 400°F for 13-16 minutes.
When they are out of the oven, if they appear puffier than you'd like, immediately smack the pan down on the counter a few times. This will help the cookies flatten and spread to a thin, chewy texture.
Take them out before they are completely cooked through-- that’s what will keep them soft!
Serve and enjoy!