A party favourite from my childhood, these couldn't be easier to make:
Makes 12 large or 24 small
250g vegetable shortening (Crisco, Kremelta)
1 cup icing (confectioner's) sugar
1/4 cup unsweetened cocoa powder
4 cups puffed rice cereal (or cornflakes if you like)
Heat the shortening in a medium saucepan on a low heat until just melted. Sift icing sugar and cocoa together and add to saucepan along with the cereal. Take off the heat and mix gently to combine. Spoon into 12 cupcake cases and chill until firm. Once firm you can store in an airtight container for a couple of days (unless your house is really hot, then maybe make them on the day and served straight from the fridge).
You could also use mini cupcake cases and make 24 small ones... very cute!