22.02.12
I adapted this recipe from a Delicious Discoveries blog and made a couple of modifications, mostly cutting out the initial chilling steps. You don't want the shortbread to get too brown in the first baking, just a pale golden, since it'll keep on baking when you bake the brownie layer on top of it. But don't underbake it either because you want it to bake enough to provide a crisp texture. Follow the proportions of the caramel layer I listed below as that set up perfectly when chilled. If you add too much heavy cream,
your caramel won't set up and will be too liquid which will
make it difficult to enrobe in chocolate. Too little cream and
your caramel will be too hard and chewy.
The last step calls for enrobing in chocolate. Normally, chocolate should be tempered first if you're going to use it as a coating. By that, I mean it needs to be melted and raised to a certain temperature, depending on the type of chocolate you use but typically it should be to 100-105 degrees F (dark chocolate on the higher end, white chocolate on the lower end, milk chocolate in the middle). Raising them to the higher temperature destabilizes the crystals.
Source: Christian Science Monitor