Preheat oven to 350°F / 177°C.
Lightly grease an 8x8 square baking pan. Set aside.
In a small saucepan over medium heat combine butter and chopped chocolate. Heat, stirring frequently, until just melted.
Meanwhile, in a medium mixing bowl, whisk together sugar, eggs, and vanilla.
Pour melted butter and chocolate into the bowl, whisking quickly to incorporate the warm ingredients.
Fold in flour until just combined. Pour into baking pan.
In a small microwave safe bowl, microwave caramels and cream in 30 second increments, stirring each time, until melted and completely smooth. (This should take about 2 minutes total.)
Drizzle caramel over brownies and use a butter knife to swirl caramel into chocolate. (I like to sort of fold some of the caramel in so that there are spots of brownie on top mixed with swirls of caramel.)
Place pretzels in a single layer on top.
Bake until edges are slightly puffed and center is just set, 30 to 35 minutes.
Let cool before slicing and serving. (Note: will slice best if the brownies have cooled completely. The caramel is extremely messy until it has cooled, but also extremely delicious. Around our house, we can rarely resist slicing into them and eating a few while they’re still warm despite the mess of sticky caramel. Just consider yourself warned.)
Store brownies in an airtight container at room temperature for up to 3 days.