1Melt the chocolate together with the butter in a saucepan over the stove in a place not too hot.
2Beat the 10 egg yolks with 5 ounces of sugar and then add them to half of the melted chocolate.
3Beat 6 egg whites very firmly and fold the chocolate mixture into them, adding at the end the 8 ounces of flour.
4Put into a butter and floured cake pan and bake for 45 minutes at low (250).
6Beat the remaining 6 egg whites until very stiff, adding 5 ounces of sugar while beating.
7Fold into them the rest of the chocolate which must be hardly warm.
8Cover the cake with the chocolate mousse.
9Then sprinkle over the top and the side grated chocolate.
10Leave the cake in the refrigerator 2 hours before serving.