Line a 8 inch – 20cm square cake tin with a layer of parchment paper.
Over a pan of simmering water, melt, in a bowl the butter, chocolate for 5 minutes or until the chocolate and butter are combined.
Meanwhile in a large bowl mix together the biscuits, marshmallows and most of the sweets and chocolate bonbons.
When the chocolate mixture has melted thoroughly pour it onto the biscuit mixture and mix well until combined.
Pour the chocolate and biscuit mixture into the lined cake tin and flatten with a spatula or mixing spoon.
Transfer to the fridge and allow to set for 3 hours.
When set, transfer on a board. Sprinkle with some cocoa powder and decorate with extra sweets.
Cut into pieces before serving and enjoy in small quantities if you can!