Place the biscuits and butter in the bowl of a food processor and process for 2-3 minutes or until the mixture resembles fine breadcrumbs. Press the mixture into a 30 cm x 20 cm lightly greased baking tray and refrigerate for 15 minutes.
Chocolate Filling
To make the chocolate filling, place the chocolate and cream in a small saucepan over low heat and stir until melted and smooth. Pour over the biscuit base and refrigerate for 30 minutes or until set.
Coffee Cream
To make the coffee cream place the cream, sour cream and liqueur in a bowl and whisk until soft peaks form.
Top the tart with the cream to serve.
Recipe Notes
You can omit the coffee liqueur and change to vanilla essence, peppermint essence or even a spice mix blend to suit your taste.