Preheat a fan forced oven to 175C (340F).
Spray an 8 by 8 inch square pan with non stick cooking spray and lay the bottom with parchment paper.
To create pretzel crust simply crush pretzels together in a food processor to a chunky crumb.
Add melted butter and continue mixing until well combined.
Add crushed pretzels to pan and press down firmly in an even layer.
Add butter and chocolate to a microwave safe bowl.
Microwave for 20 seconds at a time and repeat until it becomes smooth.
Add flour, eggs, sugar to a large mixing bowl and mix on low speed using the paddle attachment or a wooden spoon until everything is combined.
Slowly add chocolate and butter mixture while mixing on low speed.
Add batter to baking tin with pretzel crust lined with baking paper.
Bake for 30 min or until a pick comes out with moist crumbs.
Finish off with a drizzle of salted caramel sauce.