Using a food processor, Thermomix, (or even a rolling pin), crush the cookies until they resemble fine crumbs. Place the crumbs into a mixing bowl. Add the melted butter to the cookie crumbs and mix until the butter and crumbs are well combined.
Press the crumb mixture firmly into the greased loose-bottom tart tin. Refrigerate the base whilst you make the filling.
Place the brown sugar, sweetened condensed milk, and butter into a saucepan and on a LOW heat, stir continuously for at least 10 minutes, or until the caramel has considerably thickened. Once the caramel filling has a thick consistency, gently pour it over the biscuit base. Chill for at least an hour.
Slice fresh banana over the caramel filling, top with a layer of freshly whipped cream.
Sprinkle with grated dark chocolate - voila! Slice and enjoy!