Put 300 g butter, salt, vanillin sugar and 300 g sugar into a mixing bowl, whisk until thick and creamy. Add the eggs one by one and stir in. Mix flour, baking powder and cocoa and stir in alternately with crème fraîche.
Pour the dough onto a greased baking tray (35 x 40 cm), smooth it down and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 20 minutes. Remove from the oven, place on a cake rack and let it cool down.
Melt 250 g butter. Bring milk and 250 g cream to the boil in a wide saucepan. Add semolina, bring to the boil while stirring and simmer for about 1 minute. Add melted butter, 300 g sugar and 300 g coconut flakes and stir in.
Spread the mixture evenly on the cooled base, let it cool down.
Coarsely chop the chocolate coating and coconut oil. Heat 250 g cream in a pot. Add couverture and coconut oil and dissolve while stirring. Let the icing cool down for 10-15 minutes while stirring occasionally.
Spread the icing evenly on the coconut mass, smooth it down and let it dry. Cut the cake into pieces. Decorate pieces with mini coconut bars if desired and sprinkle with coconut flakes.