Preheat the oven to 350°F. Grease a 9″ x 9″ pan and set aside.
In a large microwave safe bowl, melt the butter in the microwave in 30 second intervals. While butter is hot, mix in the chopped chocolate and stir until chocolate is melted. Whisk in the sugar until combined, then whisk in the eggs and vanilla extract.
Stir in the cocoa powder, flour and salt and mix until combined. Spoon the batter into the prepared pan. Bake for 35-40 minutes, until a toothpick inserted into the center comes out with just a few moist crumbs on it.
In a medium saucepan over low heat melt the caramels together with condensed milk. Remove from heat. Stir the pretzels into the caramel mixture, they pour caramel pretzel mixture over the baked brownies and spread evenly. Let caramel layer set, then cut brownies and serve.