I saw these cupcakes on weheartit and knew I just had to try them myself!
Unfortunately, mine didn't turn out quite so well. The blue and the clouds worked fine, but the rainbow laces, which I bought from Tesco, were too thin and weak to hold their shape, so they just collapsed :( they also weren't very vibrantly coloured like the ones above are, so I'll need to find some better ones if I want to make these again.
I've got a couple more ideas I want to try next:
This idea, from My Chic Life (follow the link for the recipe) looks like a bit of a faff but it comes out so well!