Preheat your oven to 350°F and prepare a standard 9×13″ baking pan by lining with parchment paper or spraying with cooking oil.
Melt the butter in a microwave safe bowl in 30 second increments until the butter is fully melted. Next, stir in the granulated sugar and mix for 2-3 minutes until fully combined.
Slowly mix in the eggs, one at a time. Make sure each egg is fully incorporated before moving on to the next one. Then mix in the vanilla extract and salt.
Add in the flour and cocoa powder and mix until well-combined. Carefully fold in the chocolate chips and make sure they are spread evenly throughout the batter.
Pour the batter into the prepared baking pan and set aside.
To begin the cookie layer, cream the butter and sugar together in a large bowl with your electric or stand mixer until it is light and fluffy***.
Add in the egg and vanilla extract and beat the mixture well.
In a separate medium bowl, whisk together the flour, baking soda, and salt.
Carefully add the dry ingredients from the medium bowl to the wet ingredients in the large bowl. Take your time and mix in the dry ingredients slowly. Then, mix until a consistently soft dough forms. Finally, carefully mix in the chocolate chips.
Scoop out the dough into rounded balls using a dough scoop, a spoon, or your hands. Grab the brownie pan from earlier. Drop the rounded cookie dough over the brownie layer, leaving some gaps in between.
Bake @ 350°F for 25-30 minutes, or until the cookie dough areas are golden brown and the brownie layer is set. Carefully, remove the brookies from the oven and allow them to cool ~ 10-15 minutes before cutting into pieces for serving.