Melt the butter and chocolate over a very low heat, allow to cool a little. Beat the sugar and egg yolks for approx. 5 mins. until light and fluffy. Stir in the chocolate mixture. Beat the egg whites with the salt until stiff, add the sugar, continue beating until the egg whites turn glossy. Add the flour and the egg whites to the mixture and fold in carefully. Transfer the mixture to the prepared tin.
Bake for approx. 12 mins. in the centre of an oven preheated to 180°C. Remove and allow to cool in the tin.
Beat the egg yolks and sugar for approx. 5 mins. until pale and frothy. Stir in the chocolate. Dissolve the gelatine in the boiling water, strain into the egg mixture, mix well. Beat the egg whites with the salt until stiff. Beat the cream until stiff, carefully fold both into the chocolate mixture. Spread the mousse over the sponge, cover and chill for approx. 2 hrs.
Beat the cream until stiff and spread over the torte. Shave flat, thin strips from the chocolate using a knife and scatter them over the cream. Decorate the torte with the chocolate eggs.