Chop white chocolate coating. Cut butter into pieces. Melt 150 g chocolate coating and butter over a warm water bath.
Beat the eggs, sugar and salt in a large mixing bowl with the whisk of the hand mixer for approx. 3 minutes until creamy. Pour the chocolate-butter mixture into the egg mixture and stir in. Mix flour and baking powder.
Quickly fold into the chocolate-egg mixture. Stir the rest of the couverture into the mixture.
Put the dough into a greased springform pan (26 cm Ø). Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the lower rack for 15-17 minutes (stick test).
Remove and let cool on a cake rack for 15-20 minutes. Prick holes in the dough with a wooden handle close together (do not prick all the way to the bottom) and then leave to cool for 1 1/2-2 hours.
Roughly chop the chocolate. Warm the cream in a pot lukewarm. Add chocolate and melt in it at low heat while stirring constantly. Chill the chocolate cream for 20-25 minutes. Then pour over the cooled cake.
Chill the cake for about 1 hour.
Meanwhile crumble meringue with your hands and after 30-40 minutes of cooling time crumble meringue over the cake.