Despite the awful and misleading name, this combination of a biscuit base, caramel filling, sliced bananas and whipped cream is pretty amazing. It was apparently invented in England in 1972, and is well on its way to becoming a classic.
For the base
Crush the biscuits into crumbs - you can do this in a blender, or put the biscuits into a plastic bag and whack them into submission with a rolling pin. Melt the butter, and then stir it into the crumbs. Butter your pie dish (one with a loose bottom would be best) and press the mixture as evenly as you can on the bottom and sides. Put it in the fridge to chill.
For the filling
Melt the butter in a saucepan and then stir in the sugar and keep stirring until dissolved. Spoon in the dulce de leche (if you can't find this, you can make your own by boiling a can of condensed milk for 2-2.5 hours) and stir until you have a smooth mixture. Pour this into the biscuit crumb base and return to the fridge to set. This will take about an hour.
For the topping
Thinly slice the bananas and coat them in lemon jiuce. Using an electric whisk or brute force, whip the cream into soft peaks. Arrange the banana slices on top of the filling, and then spoon on the cream. Garnish with grated chocolate.
You can serve this straight away, but it will improve if you chill it for some time before serving.