Line a 1kg loaf tin with cling film. Make up the coffee with 600ml boiling water and leave for 5 minutes. Strain into a bowl through a fine sieve then stir in the sugar and amaretto liqueur. Dip the remainder as you use them into the coffee mixture and line them along the base and up the long sides of the tin (they will stand above the rim). Spoon over half of the ice-cream and even out. Sprinkle over half of the chopped toasted almonds and crumble over 10 amaretti biscuits. Spoon over the remaining ice-cream on top, then fold over the sponge fingers above the rim and press down lightly. Fill the gap down the middle with 2 more soaked sponge fingers. Press down lightly into the filling, cover with the excess cling film and freeze for at least 2 hours. To serve, turn out onto a plate, remover the cling film and dust generously with cocoa. Spoon the cream down the centre and decorate with the chocolate and broken amaretti biscuits.