Preparation of the cake should start a day before you intent to serve it, with the cream first. Combine the liquid cream and sugar in a pot on the stove, while stirring until the sugar melts completely.
Crush the chocolate in a bowl and pour the hot cream on top. Place the bowl in a water bath and stir until the chocolate is completely melted. It is important not to allow the mixture to boil. Cover thus prepared cream with transparent foil and put the bowl in the refrigerator for 1 night.
The next day, add rum or brandy and beat until you get a thick and fluffy cream. For the layers, sift the powdered sugar and add it to the ground walnuts, egg whites and vanilla. Beat with a mixer until the mixture grays and thickens.
Lay out a form or oven dish with baking paper, spread the mixture 3/4″ (2-3 cm) thick and bake 5-6 layers. Bake at around 302°F (150 °C). Remove the baked cake immediately from the form and once cool, peel off the baking paper.
In a suitable tray, stick the layers together with cream and spread cream evenly over the entire cake. For the glaze, melt the chocolate in a water bath and add the cocoa butter. Stir until homogeneous, wait for it to cool slightly and pour the glaze on the cake.