Back in May I read this article on the Daily Mail about "gravity cakes". I wanted to have a go and have been looking at ideas on Google since.
Here is the cake we made for him.
The empty bag is held up with a knitting needle inserted into a plastic drinking straw. Where the straw has the bendy end I inserted a wooden skewer to support the empty bag. It was all the wrapped in tin foil to make it food safe to insert in the cake. The tin foil had a coating of chocolate icing and we then stuck Maltesers on. This took a lot of chocolate to decorate - 2 boxes of Cadbury's fingers, 1 tub Betty Crocker chocolate fudge icing, 1 bag of Maltesers 121g and 1 bag of Maltesers 230g. It is different colours inside as Anais wanted to make a marble cake.