Stir the melted butter into the crushed biscuits and divide the crumb mixture between 4 x 220g Bonne Maman jars and chill for 10 minutes.
Slowly melt the butter and sugar together in a small, non-stick saucepan and stir with a wooden spoon to dissolve the sugar.
Stir in the caramel and bring to the boil, stirring all the time, until very smooth.
When the caramel is cold, whip the cream until it just begins to hold its shape. Fold in the coffee and continue whisking until the cream is lightly whipped.
Slice the banana and squeeze lemon over
Divide the caramel between the jars and top with sliced banana, cream and chocolate.
The jars with the biscuit base and the caramel will keep, covered, in the fridge for 2 - 3 days. Top with bananas, cream and chocolate and serve within 2-3 hours.
You can also make a baked version of this recipe here using Salted Caramel Salted Caramel Banoffee Pie