For the chocolate cake with Parisian cream, cream the butter with sugar and salt and beat in the eggs one at a time.
Beat in the melted chocolate coating and fold into the butter mixture together with the starch and baking powder. Pour into a loaf pan lined with baking paper and bake in a preheated oven for about 1 hour at 150°.
For the cream, bring the whipped cream to the boil, stir in the chopped couverture and mix briefly with a hand blender. Leave to stand overnight in the refrigerator, then carefully whip and fill the cut-through chocolate cake with Parisian cream and decorate.