For the toblerone mousse, break the toblerone or chocolate into pieces and melt in a hot water bath. Meanwhile, beat the egg whites with a pinch of salt until stiff.
Cut the butter into flakes. Remove melted toblerone mixture from heat and add butter, stirring vigorously. Now gently beat in one egg yolk at a time. Add sugar and vanilla sugar and finally fold in the snow.
Pour the toblerone mousse into a large or several small serving dishes and cover with plastic wrap and refrigerate. When cooled, garnish the toblerone mousse with fresh berries and whipped cream.