Step 1Preheat oven to 180°C. Brush a 24cm round fluted tart tin, with removable base, with butter to grease. Place biscuit and butter in the bowl of a food processor. Process to combine. Press over base and side of tin. Bake for 10-12 minutes. Set aside to cool.
Step 2Place the sugar and water in a saucepan over low heat and stir until sugar dissolves. Increase heat to high. Boil, brushing side of pan with a pastry brush dipped in water, for 10-15 minutes or until golden. Remove from heat. Stir in the cream and butter. Pour over the biscuit base. Place in fridge for 1-2 hours until set.
Step 3Pour the chocolate over the caramel and place in the fridge for a further 30 minutes until set. Dust with cocoa powder to serve.
