Method Prep:20min › Extra time:2hr chilling › Ready in:2hr20min
Put the milk, cocoa powder and Mars bars into a saucepan, heat gently, stirring constantly until melted. Transfer to a bowl and leave to cool for around 15 minutes, and whisk frequently to blend in any pieces of fudge that come to the surface to keep the mixture smooth.
In a separate bowl, whisk egg whites until they form soft peaks, using a metal spoon, fold in a quarter of the egg whites into the chocolate to lighten it, then fold in the remainder.
Turn the mixture into six small glasses or ramekins, place in the fridge to set, for at least 2 hours. Before serving sprinkle with chocolate shavings.