I just picked up the current edition of "Donna Hay Kids' Magazine" at Borders and it has a gorgeous, gluten-free cake on the cover. I'm definitely making this! This is a beautiful magazine, by the way. Although many of the recipes inside were "glutenous", I find inspiration at looking at gorgeous photographs of simple meals presented with care. Here's the link, by the way: http://www.donnahay.com.au/recipes/695-rice-crackle-cake/ Don't be daunted by the "au" in the web address. They kindly give recipe quantities in the US format as well as the Aussie style.
UPDATE: I just discovered that Rice Crispies may have gluten in them. They containly malt, which is sometimes made with wheat. As the box doesn't say "gluten-free", I think we have to assume they contain gluten. However, there are gluten-free crisped rice cereals on the market, and I also understand that Rice Chex are gluten-free and can be used whole in rice crispie treats recipes (although they probably won't work for this cake recipes as they can't be molded as well into a cake shape.)