Melt the butter, sugar & cocoa powder in a pan until everything has combined.
Pop the mixture into a bowl and add the self raising flour and egg, stir to combine.
In a lined & greased brownie tin, lay the cookie dough on the bottom and top with the oreo cookies in even strips. Top with the brownie mixture and bake at 180c for 20-22m.
Once out of the oven, remove the base of the tin and let the brownies cool.
Cut into squares and drizzle with melted white chocolate.