Preheat oven to 425. Line a rimmed cookie sheet with aluminum foil and place crackers in a single layer on the cookie sheet.
In a saucepan over medium heat, bring butter and sugar to a boil and boil for 5 minutes, stirring often.
Place the pan in the oven and bake for 4-5 minutes, or until caramel is bubbly.
Remove pan from the oven and immediately sprinkle chocolate chips over top. Let the chocolate chips set until they begin to melt, about 2 minutes, then spread into an even layer (an offset spatula works great for this). Sprinkle the top with coarse sea salt.