1. Line a lamington tin (about 30cm x 20cm x 3cm) with baking paper, making sure it hangs generously over the sides to make lifting the slice out nice and easy.

2. Place the caramels, milk chocolate chunks, Malt 'O' Milk biscuits and chocolate chip biscuits in a bowl and use your hands to gently toss and combine. Add the dulce de leche, just in spoonfuls here and there, don't try and incorporate it.

3. Add the dark chocolate to a heatproof bowl and place over a pot of simmering water, making sure the water doesn't touch the bowl. Cook until the chocolate has melted.

4. Remove from heat and pour in the condensed milk, whisking constantly to prevent the chocolate from seizing. Once the mixture has thickened, quickly pour this over the biscuit and caramel mix, stirring with a wooden spoon to coat. Scrape the mixture into the prepared tray, smoothing out the top as best you can.

5. Place in the fridge for at least 2 hours to set. Remove and allow to sit at room temperature for 30 minutes before slicing, or use a hot, wet knife to slice immediately.

Note: This will keep in an airtight container in the fridge for up to 3 weeks, if any of it lasts that long.