Lightly grease a 20cm (8-inch) square pan and line with baking paper, leaving an overhang on the sides (helps to remove the slice from the pan later). Set aside.
For the base: Place all ingredients for the base in a food processor and process for 1-2 minutes, or until the mixture resembles fine breadcrumbs. Press the base mixture into the prepared pan. Refrigerate as you prepare the filling.
For the caramel filling: Place all ingredients for the filling in the food processor (you don't have to wash it after preparing the base, just wipe it out) and process for 1-2 minutes or until smooth. It will be quite thick. Spread over the base and return the pan to the refrigerator as you prepare the ganache.
For the ganache: Place all ingredients for the ganache in a heatproof bowl over a saucepan of simmering water and whisk for 2-3 minutes or until all ingredients are incorporated and smooth. Pour mixture over the caramel filling and refrigerate for 2 hours or until set.
Freeze for 30 minutes before slicing into 4cm x 10cm bars.
Serve chilled. Store leftovers in the refrigerator; can be stored frozen as well. If frozen, allow to set at room temperature (about 10 minutes) to soften a bit.