Line a large baking sheet with aluminum foil and cover the entire pan with a single layer of pretzels.
In a saucepan over medium heat, melt butter and brown sugar until the sugar is dissolved. Let mixture boil gently for 3 minutes.
Remove from heat and pour evenly over pretzels. Place in oven for 5 minutes.
Remove from oven and immediately sprinkle chocolate chips over the top of the caramel and pretzels. Let the chocolate chips sit for a few minutes. Once they start to melt (2-3 minutes), spread evenly with a spatula. Sprinkle generously with sea salt.
Let cool on the counter top for place in refrigerator/freezer until completely cool. Break into pieces and enjoy!