Step #1
Combine the cake mix, water, vegetable oil, butter and melted chocolate.
Step #2
Pour half the brownie mix into a lined, square tin, then top with Oreos if using. Pour over the rest of the brownie mixture and smooth out. Bake at 170c for 20-25 minutes.
Step #3
Put dark chocolate and double cream into a bowl together and microwave for 1 minute 30 seconds.
Step #4
When the cake has cooked and cooled, pour the chocolate & cream mixture over it and smooth out.
Step #5
Dollop melted white chocolate and use a knife to shape into ghosts. Use the melted milk chocolate to add eyes and mouths.
Step #6
Top with sprinkles, then refridgerate for at least an hour before slicing into 16 pieces.
