Preheat oven to 350 degrees. Line 13x9 baking pan with parchment paper or grease with shortening.
Make the brownies according to the box.
Pour 1/3 of the brownie in the prepared pan. Spread out evenly. Layer the pretzels in two layers until the brownies are fully covered or you can cover with crushed pretzels.
Carefully pour or spoon the remaining 2/3 of the brownie batter on top of the pretzels. Spread carefully with a spatula or back of a spoon to evenly distribute the brownie batter over the brownies.
Cook brownies at 350 degrees for 24-28 minutes and a toothpick comes out clean from the center.
Remove from oven and cool for 5 minutes.
Pour caramel evenly over baked brownies.
Sprinkle caramel with a few pinches of sea salt.
Best if served warm topped with ice cream or room temperature.