I was convinced that I had already put the link to the Zygon Pie, but I cannot find it, so here it is again -
Doctor Who Cookbook: Zygon Pie recipe
In addition to that, here is another one for a K-9 Cake -
Doctor Who Cookbook: Kookie K-9
Both recipies , and no doubt many more, can be found in the soon-to-be-released
Doctor Who Cookbook