Blitz the biscuits and butter in a food processor until clumpy and then press the mixture into the bottom of a greased and lined 20cm deep loose bottom cheesecake / cake tin.
Put the biscuit base in the fridge for at least an hour for it to set completely.
To Make The Topping:
In a large mixing bowl whisk the cream cheese, icing sugar and vanilla extract together until well mixed.
In separate bowl or in a stand mixer whisk the double cream until soft peaks form.
Spoon cream cheese mixture into whisked double cream. Then stir in mashed bananas.
Spoon the cream cheese mixture over the biscuit base.
In a small bowl add the banana slices for the topping to the lemon juice, mix well and keep in the fridge until you are ready to serve the cheesecake.
Chill the cheesecake in the refrigerator for at least 4 hours but preferably overnight until set.
Cheesecake Topping:
When ready to serve carefully remove the cheesecake from the cake tin and decorate with the remaining sliced bananas and dust with the cocoa powder.