Preheat the oven to 350°F. Line a baking sheet with parchment paper or a silicone baking sheet.
In a separate bowl, combine the remaining dry ingredients of flour, baking soda, cornstarch and salt and set aside.
Cream the softened butter with the sugars on medium speed until well combined, 2-3 minutes.
Next, add the eggs and vanilla extract and beat until well incorporated.
Gradually add the dry ingredients into the dough, mixing on low speed until the dough starts to form.
Add the chocolate chips and chunks and beat until incorporated, without overmixing dough.
Portion out ¼ to ½ cups of cookie dough and place 3 inches apart on the prepared cookie sheet. Bake for 12-15 for ¼ cup and 15-20 minutes for ½ cup portions.
The center of the cookie should be slightly underbaked, but not to the point the cookies are gooey or shiny on top.
Allow to cool on the baking sheet for 15 minutes before transferring to a wire rack to cool completely.