Preheat the oven to 350F. Spray the 9x13 inch non-stick baking dish with a non-stick cooking spray.
Put the butter in a microwave-safe bowl and melt the butter in a microwave. Add the cocoa powder to the butter and mix with a spoon until combined.
Whisk the eggs, sugar and vanilla in another large bowl. Add the butter and cocoa mixture to the egg and mix so everything is combined. Add flour, salt and baking powder and stir until just combined (don't overmix).
Pour the brownie batter into the baking dish, put in the oven on the middle rack and bake for 25 minutes.
Make A Cookie Dough Layer
Put softened butter, white sugar and brown sugar in a large mixing bowl and mix with a mixer until combined and fluffy.
Add water and vanilla and mix until combined.
Add flour and salt and mix until combined.
Add the chocolate chips and stir them in with a spoon until incorporated.
Assemble The Cookie Dough Brownies
Let the brownie layer cool completely.
Spread the cookie dough on top of brownies.
Cut the cookie dough brownies into squares and serve.