1. Put the biscuits into a plastic bag and crush into fine crumbs using a rolling pin. Melt the butter in a medium sized pan and stir in the crushed biscuits. Press the mixture onto the base and sides of a lightly oiled, loose-bottomed flan tin – Chill for 15 minutes.
2. Spread the banoffee toffee sauce over the base of the biscuit case and cover with the sliced bananas.
3. Lightly whip the cream, instant coffee and caster sugar together in a bowl until the mixture just forms soft peaks. Spoon on top of the bananas and spread it out to make a seal with the edge of the biscuit case. Swirl the top attractively and chill for at least one hour.
4. To serve, carefully remove the pie from the tin, drizzle with warm melted chocolate and cut in to wedges.