Preheat oven to 350°F. Line a 9x9-inch baking pan with parchment paper leaving a 2-inch overhang along each side.

For the brownie batter, combine chocolate and butter in a saucepan over very low heat and stir constantly until melted and smooth, or melt in the microwave at 50% power in short bursts with frequent stirring.

Combine eggs and both types of sugar in a large bowl and beat on medium-high speed using a hand mixer or whisk by hand for 2 minutes until pale and thick. Mix in vanilla and salt. Mix in the melted chocolate mixture until evenly combined, then fold in the flour so it is evenly incorporated.

Spread the batter evenly into the lined pan. Dollop teaspoons of peanut butter over the batter and swirl it in with the back of a knife. Place pretzel twists evenly across the surface of the batter. You should be able to neatly arrange 5 rows of 5 pretzels. Bake for 25-30 minutes until the top is slightly puffed and shiny. Let brownies cool completely.

Once cooled, drizzle salted caramel sauce over top, slice and serve!