Mix 300g butter, 300g sugar, 2 eggs and 6 egg yolks until frothy. Stir in 300g grated walnuts, 300g grated semi-dark chocolate and 200g flour. Beat 6 egg whites until stiff and fold in.
Spread on a greased sheet (we take the deeper baking sheet) and bake at 200 degrees for about 20-25 minutes.
Mix 150g powdered sugar with 1 tablespoon rum and 3 tablespoons milk and brush onto the dough while it is still hot. Cut into cubes immediately.
Taste good when they have been steeped for a few days.