In a stand mixer, combine 1 cup of unsalted cold butter, 1 cup of brown sugar, and ¾ cup of granulated sugar. Beat on medium speed for 4-5 minutes until light and fluffy.

With the mixer on low, add in 2 cold eggs one at a time, ensuring each is fully incorporated.

In a separate bowl, whisk together 3 cups of all-purpose flour, 2 teaspoons of cornstarch, 1 teaspoon of baking powder, 1 teaspoon of baking soda, and ½ teaspoon of salt.

Gradually add the dry mixture into the wet ingredients in the stand mixer. Mix on low speed until incorporated.

Gently fold in 1 cup of semi-sweet chocolate chips and 1 cup of milk or white chocolate chips.

Divide the dough into 8-10 large balls, roughly 6 oz each, without flattening them.

For enhanced flavor, refrigerate the dough balls for 30 minutes to 1 hour.

Preheat your oven to 400°F (205°C).

Place 3-4 dough balls on a lined baking sheet and bake for approximately 9-11 minutes.

Once out of the oven, let the cookies cool on the baking sheet for 10 minutes.