01 -
Preheat oven to 350°F. Line a 9x13 inch pan with foil or parchment and spray with nonstick baking spray.
02 -
Melt butter and stir in dark cocoa powder; set aside.
03 -
Whisk eggs until foamy, then add sugar and vanilla extract; beat until pale yellow.
04 -
Stir the melted butter and cocoa mixture into the egg mixture until combined.
05 -
Add salt, all purpose flour, and baking powder; mix just until combined.
06 -
Spread half the batter evenly in the prepared pan. Press whole Oreo cookies into the batter, then cover with remaining batter.
07 -
Bake for 30 to 35 minutes until set. Remove from oven and cool completely.
08 -
Melt milk and white chocolate wafers separately according to package directions.
09 -
Spread melted milk chocolate evenly over cooled brownies.
10 -
Place melted white chocolate into a bag, cut the tip, and drizzle decoratively over the milk chocolate layer.
11 -
Press mini Oreo cookies into the white chocolate drizzle. Allow topping to set before cutting and serving.