Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking pan and line it with parchment paper for easy removal.
In a large saucepan, melt the butter over medium heat. Once melted, remove it from heat and stir in the granulated sugar until well combined.
Add the eggs, one at a time, mixing well after each addition, then stir in the vanilla extract.
In a separate bowl, whisk together the flour, cocoa powder, and salt. Gradually add this dry mixture to the wet ingredients, stirring until just combined.
Fold in the crushed pretzels, ensuring they are evenly distributed throughout the batter.
Pour half of the brownie batter into the prepared pan, spreading it evenly.
Drizzle half of the caramel sauce over the brownie batter, making sure to leave some space around the edges.
Carefully spoon the remaining brownie batter on top and spread it out gently. Then drizzle the rest of the caramel sauce over this layer, creating a beautiful marbled effect.
Optionally, sprinkle some extra crushed pretzels on top for added crunch.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Once baked, remove from the oven and sprinkle a pinch of sea salt on top while the brownies are still warm.
Allow brownies to cool in the pan on a wire rack for at least 30 minutes before lifting them out using the parchment paper. Cut into squares and serve.
Notes
Allow brownies to cool completely for best texture before cutting.