Add the cocoa and stir by hand. Divide the mixture into 2 parts and bake 2 layers in a 10″ (25 cm) form. Bake each at 356°F (180 °C) for about 20 min. Leave them to cool.
Cut each into 2, to obtain a total of 4 layers. Make the pudding with the milk and sugar, as directed on the package. Leave it to cool.
Similarly, make the brown cream. Pour the creams into 2 pastry bags with a round tip. Place a layer in a platter and syrup it lightly.
First, make concentric circles with the white cream, then with the brown, white again and so on, starting from the outside and going toward the middle. Cover with the 2nd layer and make circles again, this time starting with the brown cream.
Place the next layer, syrup it and put white cream, brown etc. Cover with the 3rd layer, syrup it too. Smear the whole cake with whipped cream and put it in the fridge while you make the glaze.
For the glaze, heat the cream, milk and butter on the stove. Remove and add the chocolate. Stir until it melts. Leave it to cool slightly and pour it over the cake. Decorate as desired.