Put the almonds, Brazil nuts and chocolate in a food processor and process until the consistency of ground almonds. Beat together the butter, egg yolks and 175 g (6 oz) of the sugar in a bowl until pale and creamy. Stir in the chocolate mixture.
Whisk the egg whites in a large clean bowl with a hand-held electric whisk until peaking. Gradually whisk in the remaining sugar, a spoonful at a time. Stir a quarter of the mixture into the creamed mixture using a large metal spoon. Add the remaining egg whites and stir gently to mix.
Spoon the mixture into a greased and lined 23 cm (9 inch) loose-bottomed or spring-form cake tin (see
Leave to cool in the tin (the centre of the cake will sink slightly), then remove the ring and base and dust with sifted cocoa powder. Serve with Fresh Raspberry Compote, if liked (see below).