Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper, ensuring it covers the sides for easy removal later.
Spread the broken pretzel pieces evenly across the baking sheet, creating a single layer.
Bake the pretzels in the preheated oven for about 5-7 minutes or until they are slightly toasted. Keep an eye on them to prevent burning. Remove and allow to cool slightly.
In a microwave-safe bowl, combine the semi-sweet and dark chocolate chips. Heat in the microwave in 30-second intervals, stirring in between until the chocolate is fully melted and smooth.
Pour the melted chocolate over the pretzels, using a spatula to spread it evenly across the pretzel layer.
Drizzle the caramel sauce over the chocolate-covered pretzels, ensuring even coverage. Use a toothpick or a small spatula to swirl it gently into the chocolate for a marbled effect.
Sprinkle the sea salt over the top, ensuring an even distribution. If desired, add the chopped nuts for an extra crunch.
Place the baking sheet in the refrigerator for at least an hour or until the chocolate and caramel are completely set.
Once set, break the bark into pieces of your desired size and store in an airtight container.