To make base layer, add all ingredients to a food processor and pulse until combined.

The mixture should appear crumbly, but should hold when pressed together between two fingers.

Press firmly into a loaf pan or small slice pan (15 x 23 cm/ 6 x 9 inches).

Place in the freezer while you make the caramel layer.

To make the caramel, melt the butter in a small saucepan over medium to low heat, stirring constantly, until its started to brown.

Add the remaining ingredients and stir until combined, then reduce heat until just simmering, and cook 5-10 minutes or until it starts to thicken.

Note that it will continue to thicken as it cools.

Pour over the base layer, and spread evenly.

Return to the freezer while you make the chocolate layer.

Melt the chocolate in a small saucepan or in the microwave, and then pour onto the solidified caramel layer.

Spread evenly.

Place back in the freezer for at least an hour to set.

Once set, cut into squares or bars, and store in an airtight container in the fridge.

To get 18 small squares: make 2 cuts lengthwise and 5 cuts widthwise.

Alternatively to make 12 large bars: make 2 cuts lengthwise and 3 cuts widthwise.

Keeps up to 10 days in the fridge, or two months in the freezer.