I don't know anything about cake I'm afraid. However if what you are wanting is this:
Then you can do this using the normal html codeblock/iframe combination. I sound like a cracked record (for those that remember them) as I always seem to end up sayng the same thing. Well, either a cracked record or an old man who just sits in the corner of the pub muttering the same thing to himself over and over again: "codeblock, iframe, codeblock, iframe…"
So what you need is an html codeblock with your script inside it:
[[code type="HTML"]]
<html>
<body>
<script type="text/javascript" src="http://feeds.delicious.com/v2/js/tags/dpc.ucore.info?title=&count=100&sort=alpha&flow=cloud&name&showadd&color=73adff-3274d0&size=12-20"></script>
</body>
</html>
[[/code]]
Wrap that in [!-- --] comment tags.
Then reference that codeblock with an iframe:
[[iframe http://strathviewconsultants.wikidot.com/support:sandbox/code/12 frameborder="0" scrolling="no" width="300px" height="250px"]]
It was the 12th codeblock on that page which is why it says /code/12. More likely it will be your first or only codeblock so use /code/1.
Which gives the result above.
Simples.

Rob