For the layer, beat the butter with the sugar and eggs, until you get a smooth cream. Mix the flour, cocoa and baking powder, alternating them with the milk while constantly stirring and adding them to the cream. Smear a 10 (26 cm) diameter form, pour in the mixture and put it to bake for 25 min. in a preheated 356°F (180 °C) oven.
Release the prepared cake from the form and leave it to cool.
Melt the couverture chocolate slowly in a water bath and pour it over the cake. Put the Cake with Chocolate and Coconut for several hours in the fridge before serving.