In a saucepan, melt the sugar, then add cream and stir well until a smooth caramel is formed.
Add a pinch of freshly ground salt.
In a saucepan, melt butter and chocolate over low heat.
Remove from heat and add cocoa, then eggs, one at a time, mixing well after each.
Add the sugar, vanilla, flour and walnuts.
Mix well and place half the mixture in a cake pan greased with butter.
Add spoonfuls of caramel, cover with the remaining batter and bake in preheated oven at 350°F for approximately 30 minutes.
Serve with ice cream.