White chocolate mud cake recipe here. This has become my default kid's cake recipe. Most kids like it, and it's a lovely texture. I did it tired, pregnant and in a rush, dumping all the ingredients in together, and it was still fine.
The technique for the chocolate bird is from here and Astrid's instructions are better illustrated than mine (what with Astrid being a visual explainer and all). Basically I traced the bird from this illustration:
from the remarkable picture book Fox by Margaret Wild, illustrated by Ron Brooks.
I then laid baking paper over my tracing and drew the outline again in dark chocolate with a piping bag and small nozzle. I filled in the gaps with melted pink chocolate (the pink chocolate came from a specialty chocolate shop and was pink flavour (strawberry I guess). Then I reinforced it with more dark chocolate, put it in the fridge and freaked out for half an hour or so that everything was going to go horribly wrong. Then when it was set and hard I flipped it over and put it on the cake (slightly askew and quickly realised that it was there to stay). It was surprisingly easy, amazingly effective and tasted great. Tara - bless her - said, in the clear, truthful tone of a guileless six year old: 'That is the best cake I have ever seen.'