Mix together the flour, cornstarch, pumpkin pie spice, baking powder, baking soda, and salt in a large mixing bowl until well combined.
In a separate large mixing bowl, beat together the granulated sugar, brown sugar, and melted butter with an electric mixer on medium speed until well combined. Beat in the eggs, vanilla, then pumpkin until well combined.
Beat the flour mixture into the sugar and butter mixture until combined. Stir in the chocolate chips.
Scoop the cookie dough out onto a parchment paper or silicone mat lined baking sheet. Flatten the dough slightly with your hand. Refrigerate the dough for about 30 minutes or until dough is chilled.
Preheat your oven to 325 degrees F.
Spread cookies out on lined baking sheets. Bake cookies for about 14-18 minutes, rotating pans halfway through baking. Cool cookies slightly on pan, then remove cookies from pan with a spatula and place cookies on wire racks to finish cooling.
SNAPPY TIPS: Be sure to use canned pumpkin and not canned pumpkin pie.SNAPPY SUBSTITUTIONS: Instead of mini chocolate chips, you can substitute regular size chocolate chips, chopped chocolate, or your favorite mix-ins like other baking chips, toffee chips, or chopped nuts.