To prepare the pretzel shortbread:
- Preheat the oven to 350 degrees and line an 8” square metal pan with a sheet of aluminum foil.
- Crumble pretzels until they form a coarse sand consistency. You can leave a few small chunks, if desired. In a medium-sized bowl, stir together the pretzel crumbs, flour, brown sugar, and salt until combined. Add the butter and stir to bring together. Pat the mixture out into the bottom of the prepared pan and bake in the preheated oven until the shortbread is soft but slightly set, about 20 minutes. Allow to cool briefly while you prepare the caramel filling.
To prepare the caramel filling:
- 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 pretzel shortbread and set aside to cool completely. You can expedite this process by refrigerating it.
To prepare the chocolate ganache:
- Heat the heavy whipping cream until hot but not simmering. Place the chopped chocolate in a heat-safe bowl and pour the cream over top. Cover the bowl in plastic wrap and allow the chocolate to melt for about 5 minutes. Stir the chocolate and cream together until smooth, microwaving in 10 second spurts as needed to help melt unmelted chocolate. Smooth the mixture over top of the caramel filling and garnish the top with extra pretzels or flecks of salt. Allow to cool completely before cutting into pieces.