Me and my spouse have a birthday related tradition – each birthday the hero of the day gets to wish for look a for the birthday cake he/she will receive. So far the realized wishes have included for example Spiderman, an elk, Hobbes, etc. One thing that never crossed my mind though was to wish for a cake which would look like cat litter. However it seems, that the imagination of some people do not seem to have limits. Here is a cake baked by Andrea James, which indeed does look like cat litter.
The detailed instructions on how to bake your own cat litter cake can be found from here (particularly noteworthy is the instruction to use fresh, NON USED litterbox)