• Place the Toblerone, dark chocolate and butter in a medium saucepan and cook over low heat, stirring with a rubber spatula until the chocolate has melted. Remove from heat.
• Add the egg yolks, one at a time and stir until combined.
• Allow the mixture to cool completely (put it in a large mixing bowl, to cool down faster).

When mixture has cooled

• Use a hand mixer to whip the cream until thick.
• Now whisk the egg whites until stiff peaks form.
• Take some of the cream and gently fold it through the cooled chocolate mixture.
• Now fold through a third of the egg whites and continue to alternate between the cream and egg whites until everything is combined.
• Pour into serving bowl or individual glasses and refrigerate for several hours (preferably overnight).
• You can decorate with Chantilly cream and chocolate shavings, if desired.