Use unsweetened cornflakes, and mash them up a bit otherwise the mix can bea bit crumbly and the 'biscuits' don't hold together properly.
Afghans
6 oz flour
3oz sugar
2 oz cornflakes
1 oz cocoa
7 oz butter
Mix together, squash dessertspoonfuls into a rounded mound, bake in a moderate over (170-180 degrees C) for 16 minutes. When cool, ice with chocolate icing and top with half a walnut.
(My colleague suggested using Nutella..... now there's innovation for you.)
Pictured with, or without, flash lighting.... the flash certainly makes them look more chocolatey.