The sugar dissolves in the milk, water and what not, to form a syrup that cements the fibres and starch strongly to the ceramic while wet. The fibrous bits in the syrup form a matrix like the fibres in fibreglass, preventing the hard, sugary mass from cracking. They also lend it "give" if you apply force to it. When the lump dries you have a strong adhesive holding resilient fibres in a hard, sugary mass. Pretty strong!
The solution (OK, I suppose you could call that a pun!) is to leave the plates soaking in water, preferably warm, till the sugar has dissolved all the way through. Never mind the detergent at that point, and you do not need lots of water even. Then go away and do something sensible for an hour or two, anything reasonably legal and satisfying that will keep you away from the sink. The sugar will re-dissolve, and after that the merest gentle sloshing will produce a clean plate.
Of course, if you put the dirty plate into water for washing before the cereal hardens, that would be pretty sensible too, though not as much fun as some of those legal things you could have done instead.
Yet another option is to stop eating that exorbitant, messy, frosted fangrot. You can make yourself a low-GI muesli-type breakfast that will keep morning munchies at bay for hours. Use some nice, cheap breakfast oats, not necessarily quick-cooking, some bran (real, if you can get it; most of the so-called bran flakes might as well be frosties), and no sugar. Instead add a few cheap raisins or other dried fruit (soaking in advance optional). Add hot milk, and no other breakfast is necessary, though we personally prefer to have some coffee as well.
You will howl with disgust until you get used to it (two or three days usually) but afterwards you will wonder how anyone else survives. It even tastes good. You might want to assault anyone who offers you frosted "cereal" instead. If you want to add nuts, tasty seeds or the like, feel free, but they are not really necessary. Animal tissue addicts would want some kipper or bangers as well, but for our part we reserve that sort of debauchery for when we can indulge our baser tastes in a hotel or B&B. We have on occasion had some really good British bacon (British bangers are unspeakable!!!) in Blighty B&Bs though I am sure there is by now some virtuous EEC regulation against them. I would recommend that you send some of your sausage makers to South Africa to learn to make boerewors, but if the gnomes in Brussels cottoned on, they probably would forbid that too...
Bon appetite!
Jon
