Mix the margarine, sugar, vanilla sugar and eggs until frothy. Add the cinnamon. Then stir in the cream (not whipped). Mix the flour and baking powder, sieve and stir in. At the end sift the cocoa and stir in.
Spread the dough on a greased baking sheet and bake at 180 ° C for about 25 minutes. Brush the cooled cake with chocolate icing and sprinkle with nonpareille.