Preheat the oven to 175 degrees. Line a small bread pan, about 8X18 cm, with aluminum foil. Melt the chocolate and butter together. Whisk the eggs and cream separately with an electric whisk. Mix all the ingredients together. Pour the batter into the mold and top with coarsely chopped chocolate and nuts. Bake in the middle of the oven in a water bath for about 30 minutes. The consistency should start to become firm, but still be sticky in the middle.