From novelty cakes to birthday cakes, and croque-em-bouche to traditional wedding cakes, presenters Simon King and Dave Myers delve into the world of celebration cakes and face their biggest challenge to date. In this programme, the Hairies are tasked with making a five-tier wedding cake. On a quest to find out more, Dave and Si visit Patisserie Viennoise in Otley, Yorkshire, where they learn about the art of chocolate. To get up to speed cake-wise, Dave and Si start by making not one, but two tailor-made birthday cakes for four-year-old twins. Finally, the Hairies journey to Manchester to meet Helen and Jonnie, the couple who are prepared to let them loose on their wedding cake! The boys decide to bake a traditional fruit cake, with a Hairy Bikers twist. Using quantities of ingredients so large, the cake has to be mixed in a wheel barrow! After baking and marzipanning the cakes, the boys attend sugar craft lessons before they attempt to begin decorating and then constructing the five tiers. It's art meets engineering for the boys, and for the bride and groom as they are followed in the nail-biting lead-up to their wedding.