Preheat oven to 170 degrees C and lightly grease a cake tin.
Start by creaming the butter and sugar together until they're light, pale and fluffy. Beat the egg yolks thoroughly together and add them to the mixture, about a teaspoonful at a time, beating well after each addition. When all the yolks are in, lightly fold in the almond meal, grated chocolate and milk.
In a separate, dry, clean bowl, whisk the egg-whites till they reach the soft peak stage then fold them into the rest of the mixture gently and carefully. Next gently fold in the flour.
Spoon the mixture into cake tin, level it off, place it on the centre shelf in the oven and bake for 1 hour 10 minutes or until the centre is springy when touched lightly. Allow the cake to stand in the tin for 5 minutes, then turn it out on to a wire rack to cool.
To decorate: melt the chocolate in a heatproof bowl over a double boiler or in the microwave. Allow it to cool for 2-3 minutes and then stir the cream into the chocolate.
Split the cake in half and use half the chocolate to sandwich it together and the other half to spread over the top, making patterns with a knife. Decorate with toasted almonds.