Combine salt, flour, and unsweetened cocoa powder into a large bowl then stir to combine. Set aside.
Add the melted butter, brown sugar, and white sugar into a large bowl and mix with a hand or stand mixer and mix on medium for 2 minutes.
Add the vanilla extract, olive oil and eggs to the same bowl and mix an additional 2 minutes on medium.
Add in the dry ingredients and stir until just combined. Finally add in the chocolate chips and stir then prepare the cookie dough.
For the Cookie Dough
Combine salt, baking powder, baking soda, and flour into a large bowl and stir to combine. Set aside.
In a separate bowl mix the softened butter, brown sugar, and white sugar with a hand or stand mixer on low until well combined. Add in the egg and vanilla extract and continue to mix.
Once combined, add in the flour mixture slowly to the wet ingredients and mix on low until combined and no flour remains.
Finally, stir in the chocolate chips then assemble the brookies.
Preheat your oven to 350 degrees and line a 9x13 inch baking pan with parchment paper or spray with cooking spray.
Scoop large spoonfuls of cookie dough and brownie batter into the baking dish evenly covering the entire thing. Using a knife gently swirl the two together so no gaps remain and the brookies are in an even layer.
Cover the dish with foil and bake on the center rack for 20 minutes. After 20 minutes remove the foil and bake an additional 15-20 minutes until the top is golden and a inserted toothpick comes out clean. Slice and enjoy warm.
Notes: Leftover Storage: Store leftover Brookies in an airtight container for up to 1 week.