How to make
Beat the 8 eggs, sugar and vanilla. To the resulting mixture, add the flour, which you've mixed with the baking powder and half the carbonated water.
Divide up the mixture into 3 identical bowls. Add the cocoa to one of them for the brown layer, leave the others yellow. Bake the cake layers 1 by 1 in a buttered and floured tray.
To make the cream, put 3 4/5 cups (900 ml) of the milk in a pot to boil on the stove with the sugar and vanilla for it.
Next, beat the yolks with the flour and remaining milk, pour this in a thin trickle into the pot, while stirring nonstop. Add the butter. Leave the cream to cool a bit.
Stack the cake layers, alternating between yellow, brown and yellow, while pouring carbonated water on top of each layer to syrup them, pour cream and then place the subsequent layer.
Optionally, you can sprinkle with grated chocolate, walnuts or other kinds of sprinkles.