Mix butter, sugar and eggs well until foamy, stir in flour, cocoa and baking powder. Bake the dough in a well-greased 20 x 28 cm baking pan for about 20 minutes, leave to cool.
Heat milk, butter and semolina, cook to a thick semolina porridge, stir in sugar, desiccated coconut and vanilla pulp, spread on the chocolate dough. Heat the couverture and coat the coconut mixture with it.
Chill for a few hours. Then cut into pieces of the same size.