To make the base, process the biscuits until crushed. Stir in the melted butter. Press the mixture into the base of a lined, spring-form tin. It is important that the biscuits are 4cm up the sides of the tin. Chill the base in the fridge while you prepare the filling.

To make the filling place the butter and sugar into a non stick saucepan over low heat, stirring until the butter melts and the sugar dissolves. Add the condensed milk and bring gently to the boil, stirring continuously. When the caramel has started to boil, remove from the heat and pour over the biscuit base. Cool, and then leave to chill for about an hour or until firm,

To serve, remove the set pie from the tin and place on a serving plate. Slice the bananas and carefully fold half of them into the softly whipped cream. Spoon this mixture over the caramel base. Decorate with the remaining bananas and finish off with the grated chocolate.