To prepare the shortbread:

1. Preheat the oven to 325 degrees and use a large sheet of aluminum foil to wrap the insides of an 8 or 9” square metal pan with overhang on the sides.
2. In a large bowl or the bowl of a stand mixer, cream the butter and sugar together until well combined and smooth, about 1-2 minutes. Add the flour and salt and stir just until combined into loose crumbs. Dump the mixture into the prepared lined pan and press it evenly into the bottom. Bake in the preheated oven until the top is golden, about 30-35 minutes. Set aside to cool slightly while you prepare the caramel filling.

To prepare the caramel filling:

1. In a medium saucepan over medium heat, cook the butter and sugar together, stirring occasionally until the butter has melted.  Add the sweetened condensed milk and corn syrup and bring the mixture to a boil. Begin stirring continuously and cook for 5 minutes, or until the mixture has turned lightly golden and has thickened to a mayonnaise consistency. Remove from the heat immediately and stir in the salt. Pour the mixture over the shortbread and set aside to cool completely. You can expedite this process by refrigerating it.

To prepare the chocolate crunch:

1. Once the caramel layer has set, place a large bowl over a slightly small saucepan filled with 1” of water. Place the pan over medium-low heat and add the chocolate to the bowl, stirring regularly to gently melt it. Be sure to not let the chocolate overheat or it may seize. Once melted and smooth, fold in the rice cereal and then spread the mixture over top of the set caramel layer. Allow to cool completely before cutting into bars and serving.