Beat 4 eggs with 100 gram sugar for 5 minutes. Add the flour and 100 gram butter and stir carefully. Pour the batter in a greased baking tray and bake the cake 30 minutes at 180 degrees Celsius. Allow it to cool down and slice it in 2 layers. Dissolve the corn starch in 2 tablespoons orange juice; split the remaining eggs and add the 2 egg yolks. Bring the rest of the juice to the boil with the remaining sugar, add the corn starch mixture and heat slowly while stirring until it has thickened. Add 25 gram butter and stir. Distribute this mixture over the bottom layer of the cake and close with the top layer. Heat the cream with the chocolate and the remaining butter until the chocolate has melted. Allow this to cool down and whisk the mixture a minute. Cover the top side of the cake with it.