Preheat the oven to 175 ° C and use the resulting heat to melt the chocolate on a heat-resistant plate. Mix the first four ingredients together until the sugar has completely dissolved. Mix the ground hazelnuts with the baking powder into the batter. Add the liquid chocolate and pour the (rather soft) mixture into a bundt pan.
Bake at 175 ° C for one hour. After about 20 minutes, put a piece of aluminum foil over it so that it doesn`t get so dark.