In a large mixing bowl, add the butter, brown sugar, and granulated sugar. Using a hand mixer on medium speed, beat until any butter chunks are no bigger than a pea size and creamed, about 1 to 2 minutes.

Add in the eggs and vanilla extract. Beat until the eggs are worked into the batter.

Add the flour, cornstarch, baking powder, and salt. Beat on low until most of the flour is worked into the batter and then turn the mixer to medium and continue beating until well incorporated.

Add in the chocolate chunks and fold in with a spatula until evenly distributed.

Scoop the cookie dough into 4 tablespoon balls. I use an extra large pampered chef ice cream/cookie scoop to scoop mine.

Scoop the cookie dough and place on a parchment paper lined baking sheet that has sides.

Place in the fridge to chill for 30 minutes to 1 hour.

Preheat the oven to 400 degrees F while the cookie dough is chilling.

Place the chilled cookie dough 2 inches apart on a parchment lined cookie sheet.

Place in the oven (I like to place these cookies the second height from the top of my oven and I have have 5 heights so just above the middle rack) and bake for 12 minutes or until the edges of the cookie are golden and the top of the cookie is no longer shiny. It will appear dull like the rest of the cookie.

Remove from the cookie sheet immediately and place on a paper towel or wire rack to cool.

Store in an airtight container at room temperature.