MAKING
1 In a bowl, melt chocolate over a pan of hot water.
2 Beat the softened butter with half the sugar until pale and creamy.
3 Beat in cocoa and coffee.
4 In a clean bowl whisk egg yolks with the remaining sugar until creamy.
5 Whisk in rum.
6 Beat the slightly cooled, melted chocolate into the cocoa mixture.
7 Fold in the egg mixture and the whipped cream.
8 Line a deep 6" (15 cm) souffle dish with cling film.
9 Spread a little of the chocolate mixture on the sides of the sponge fingers and arrange with sugar side out, around the dish.
10 Spoon in the remaining mixture to the dish.
11 Chill for at least 4 hours until firm.
12 Trim the sponge finger to the same height as the filling.
13 Shortly before serving turn out onto a plate and decorate the top with rosettes of whipped cream and sprinkle with crumbled flake.

SERVING
14 Freeze in individual portions.