Beat granulated sugar, brown sugar, and softened butter in a stand mixer.
Add in egg, milk, and vanilla extract into the first mix as it is blending.
Whisk flour, baking soda, and salt in a separate bowl.
Gradually add this to the stand mixer.
Add a cup of chocolate chips.
Preheat the oven to 325 Fahrenheit degrees.
Coat a deep pan with cooking spray.
Spread mixture evenly in the pan.
Top the dish 1/2 cup of chocolate chips.
Bake in the oven until golden, about 25 minutes.
When done let sit for 15 minutes.
Cut into wedges and serve them.