To make the ultimate birthday cake for Pat’s 70th, Roger, Alan and Ped conspired to create a cake with a difference…

Firstly we experimented with bicarbonate of soda, vinegar, lemons, crushed vitamin tablets, citric acid, kitchen knives, expanding foam, chocolate eggs, water bomb balloons, polystyrene, food dye, washing up liquid and a large quantity of icing sugar to find the right materials.

We constructed a cake that would, when cut, burst a balloon inside and release the mixture of vinegar, food dye and washing up liquid over the reactive mixture of bicarbonate of soda, citric acid and crushed vitamin tablets.

The expanding morass of foaming green ectoplasm would rush through a hole underneath the main decoration, which was Paul’s rendition of life model perched on top of the cake being painted by a tartan clad artist in front of his easel.

Experimentation and construction: