Preheat your oven to 180°C. Line two baking trays with baking paper.
Beat the butter, sugar and vanilla extract until it becomes light and fluffy. Sift in the flour and cocoa and mix until just combined. Add the cornflakes and mix gently.
Scoop up a tablespoon of batter, roll it into a ball and place it onto the baking tray. Gently press down using a fork. Bake for 15-20 minutes. Let the biscuits cool, preferably on a cooling rack, before icing.
Place the icing sugar, cocoa, vanilla extract, water and melted butter into a large bowl. Mix using a fork. Add more water until you are happy with the consistency. I used little water to have a thick icing for my biscuits.
Spread the icing on top of the biscuits using a teaspoon. Top with walnut pieces in the centre.
Makes around 14-16 biscuits.
Servings 0
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.