1. Make the pretzel crust:  Preheat oven to 350 degrees.  Mix together melted butter, sugar and crushed pretzels.  Line bottom of a 12 X 9 baking pan with parchment paper; evenly spread pretzel mixture on top.  Bake crust for 6 minutes.

In a medium bowl; mix together flour, baking powder and salt. In a large bowl; microwave together 2 sticks of melted butter and the chocolate for around 1 minute. Continue microwaving until melted; stirring every 30 seconds. To the melted chocolate; add eggs, sugar and vanilla. Mix until combined. Stir flour mixture into the chocolate mixture. Pour brownie batter over the top of the pretzel crust and bake for around 30 minutes or until toothpick comes out clean. Allow to cool slightly and lift out of baking pan. Cut brownies into squares and top with caramel sundae sauce; kosher salt and a pretzel before serving.