Ingredients: -
225 g / 1 cup Butter – room temperature,
100 g / 1/2 cup Sugar,
160 g / 1 1/4 cups Flour,
25 g / 1/4 cup Cocoa Powder,
200 g / 2 cups Corn Flakes 
Chocolate Icing: -
30 g / 2 Tbsp Butter,
125 g / 1 cup Icing Sugar
15 g / 2 Tbsp Cocoa Powder,
2 Tbsp Boiling Water,
Walnut Halves 
METHOD: -
In a medium sized mixing bowl add in the butter and sugar. Cream these together with a hand mixer for a few minutes until the light and fluffy. Make sure you are using room temperature butter here or it will be much harder to cream it with the sugar.
Sieve flour and cocoa powder and add to the butter and sugar, mix well.
Add the cornflakes to the dough folding them in gently until just combined.
Take tablespoon sized amounts of dough and roll into balls, place on the baking tray.
Lightly flatten with your fingers or use the back of a spoon.
Bake the Afghans in a 180°C oven for 15-20 minutes. Cool on the tray for 15 minutes before transferring to a wire rack to cool completely before icing.
To make the Chocolate Icing: - 
In a medium sized mixing bowl, add the icing sugar, cocoa powder and room temperature butter.
Slowly add the water a little at a time until the desired consistency is reached. If you accidentally add too much water just add a little icing sugar.
Add about a tablespoon of the chocolate icing to each of the afghan biscuits and spread it with the back of a spoon. Top each afghan with a walnut half and leave for 20-30 minutes for the icing to set.