Heat a skillet on medium and add the butter. Cook the butter until it melts and then begin to stir continuously. Keep cooking and stirring until the butter being to turn brown in color and smells nutty. Immediately remove from heat and store in a container. Chill uncovered until almost entirely solidified, but still somewhat soft.
Preheat the oven to 350 degrees F. Line two baking sheets with parchment paper or a silicone baking mat.
While the butter is chilling, mix together the flour, baking soda, salt, corn starch, and spices in a medium bowl. Set aside.
Remove the butter and place in a bowl. Beat the butter with both the brown sugar and granulated sugar until light and fluffy.
Add the pumpkin puree and vanilla extract and beat until well incorporated.
Slowly add in the flour mixture and mix until it is just incorporated into the butter mixture. Fold in the chocolate chips.
Chill the cookie dough for at least an hour.
Make balls of cookie dough that are two tablespoons big and place on the baking sheets at least two inches apart.
Bake for 8 -10 minutes, or until the edges are a light golden brown.