How to make
Cake layer:
Beat the butter with the sugar, until a homogeneous mixture is obtained.
Add the eggs, cocoa, walnuts and the flour towards the end.
Bake the chocolate fudge layer in a pan. Leave it to cool.
The glaze:
The chocolate couverture is broken into small pieces and melted, in order to make a glaze for the fudge.
Add the milk and butter, while stirring at all times.
Spread the fudge with the warm glaze and leave it in the refrigerator for 30 minutes.