Sometimes my son comes up with excellent ideas; a few weeks ago when I collected him from school on Friday afternoon he had one request for the weekend: to bake a vanilla rainbow cake.
On the Saturday we took a trip to Sainsbury and bought all the necessary ingredients, including six colours of food colouring (Dr Oetker gel food colourings; my son was a little disappointed when I said we wouldn't be having an indigo layer - dark blue is hard to make in cake) and set about baking six brightly coloured sponge cake layers.
The following morning, I whisked up some butter icing and we make a beautiful (rather unstable) stack of rainbow cake. To stop the pile collapsing I had to push two straws through all the layers, not an elegant solution, but it did stop the cake collapsing on the floor.
This bake was really good fun, and very tasty at the end. I would definitely recommend giving it a go if you have small (or not so small) children. Use a smallish tin unless you have loads of mouths to feed (ours was 6 inches wide and we managed to finish it between six of us in a couple of days), and if you want a slightly more stable cake, make them thicker than you want them to be and trim them so they're level. I'd still recommend using some supports though, unless you like to eat your cake off the floor!