Preheat oven to 350 degrees. Line an 8 x 8 metal baking pan with parchment paper and set aside.
In a large bowl, whisk together melted butter, both sugars and vanilla until combined.
Add eggs, one at a time, whisking vigorously after each addition until well incorporated.
Stir in cocoa powder, salt, flour and chocolate chips until *just* combined. Avoid overmixing.
Add half of the brownie batter to baking pan then smooth top with a spatula.
Arrange 12 Oreo cookies in a single layer on top of batter.
Top Oreos with remaining brownie batter the smooth top with a spatula.
Sprinkle batter with 12 crushed Oreo cookies.
Bake for approximately 25 minutes or until a toothpick inserted into the center comes out with a few moist crumbs. Avoid overbaking or brownies will be dry.
Remove pan from oven and place on a baking rack to cool completely, approximately 1.5 to 2 hours.
Slice and serve.
Cover and store leftovers at room temperature up to 1 week.