Stir together the ground almonds and
sugar, then beat in the egg yolks, vanilla essence and chocolate.
Whisk the egg whites until very stiff, then fold into the chocolate
mixture using a metal spoon. Spoon into a greased and lined 20 cm/8 in
cake tin (pan) and sprinkle with the chopped nuts. Bake in a preheated
oven at 190ºC/375ºF/gas mark 5 for 25 minutes until well risen and
springy to the touch.