For the dough, mix the butter, eggs, sugar, sour cream, Nutella, baking powder and flour into a smooth dough with the mixer. Place in a greased wreath dish and bake for 40 minutes at 200 degrees top / bottom heat.
For the ganache, heat the cream on the stove. Put the chocolate in the pot and melt it too. Let cool for 2 hours.
Then smooth the cooled cake with ganache and decorate with chopped chocolate candies and fondant circles.