Preheat oven to 350 degrees F and line a 9x13-inch metal baking pan with parchment paper, set aside.
In a large mixing bowl whisk the melted and cooled butter, sugar, eggs and vanilla extract until well combined.
Add the flour, cocoa powder, salt, baking powder, and white chocolate chips and mix with a wooden spoon or rubber spatula until just combined.
Pour half the batter into the prepared pan and spread evenly.
Layer 24 Oreos in a single layer over the batter.
Pour the remaining batter over the brownies and smooth it out to make it even.
Crush up the remaining 10 Oreos in large pieces and scatter on top of the batter.
Bake for 28-32 minutes. It’s a bit harder to tell when these brownies are done because if you put a toothpick in, they will likely hit an Oreo in the middle. Watch for the center to look set, dry, and starting to crack.
Remove from the oven and let the brownies cool at least 15-20 minutes before slicing.