1. Prepare the shortbread base:
- Preheat your oven to 180°C (160°C fan) or 350°F. Grease and line a 9×9 inch baking tin.
- In a mixing bowl, combine the flour, butter, and sugar. Rub the butter into the flour and sugar until the mixture resembles fine breadcrumbs.
- Press the shortbread mixture evenly into the prepared baking tin, creating a firm layer.
- Bake for 20 minutes or until golden and firm to the touch. Set aside to cool completely.
2. Make the caramel filling:
- In a saucepan, melt the butter and sugar over low heat, stirring until dissolved.
- Add the condensed milk and bring the mixture to a gentle boil, stirring constantly to avoid burning.
- Let it simmer for 5-7 minutes, or until it thickens and turns a golden caramel color.
- Pour the caramel over the cooled shortbread base, smoothing it out with a spatula. Allow the caramel to set in the fridge.
3. Prepare the chocolate topping:
- Melt the chocolate in a heatproof bowl either in the microwave in 30-second intervals or over a saucepan of simmering water (bain-marie).
- Once melted, pour the chocolate over the set caramel, spreading it evenly with a spatula.
- Place the tin back in the fridge to set for at least 1-2 hours, or until the chocolate has hardened.
4. Slice and serve:
- Once set, remove the shortbread from the tin and slice into squares or rectangles with a sharp knife.