3 oz (75 g) Amaretti biscuits, crushed finely with a rolling pin
1 lb (450 g) dark chocolate (75 per cent cocoa solids) – the best quality possible
5 tablespoons liquid glucose
5 tablespoons rum
1 pint (570 ml) double cream, at room temperature
cocoa powder for dusting
chilled single pouring cream
9" / 23cm cake tin, lined with a circle of baking parchment, and the base and sides lightly greased
sprinkle the crushed biscuits all over the base of the tin. Break the chocolate into sections and put them in a heatproof bowl together with the liquid glucose and the rum. Fit the bowl over a pan of barely simmering water, then leave it until the chocolate has melted and become quite smooth. Stir, then take off the heat and leave the mixture to cool for 5 minutes or so until it feels just warm.
in a separate bowl, beat the cream until only very slightly thickened. Fold half into the chocolate mixture and then fold that mixture into the rest of the cream. When it is smoothly blended, spoon it into the prepared tin. Tap the tin gently to even the mixture out, cover with clingfilm and chill overnight.
just before serving, run a palette knife round the edge to loosen the torte, then give it a good shake and turn the whole thing out on to a serving plate (don't be nervous about this – it's very well behaved). To serve, dust the surface with sifted cocoa powder and, if you like, mark the top into serving sections. Have some chilled pouring cream to go with it; if you have any, a couple of tablespoons of amaretto liqueur makes a wonderful addition to the cream.