Break up the chocolate oranges, add 200g into a heatproof bowl. Keep the rest for garnish.
Melt the chocolate over a pan of simmering water. Once melted take off the heat and leave to cool slightly.
Meanwhile, whip the cream to soft peaks.
Separate the egg whites from the yolks. Add the yolks into the cream with the golden caster sugar and whisk to combine.
In a separate bowl, and using a clean whisk, beat the egg whites with a pinch of salt until you have stiff peaks.
Fold the cream mix through the melted chocolate. Then carefully fold the stiff egg whites through.
Divide into glasses or ramekins. Chill in the fridge for at least 4 hours, but ideally overnight.
Garnish with whipped cream, leftover chocolate orange and orange zest.