Line a 9-inch square dish with parchment paper, leaving some overhang for easy removal.
Combine the brown sugar, butter, and sweetened condensed milk in a saucepan over medium-low heat.
Stir constantly as the mixture begins to melt and bubble, releasing a sweet, buttery aroma. Continue stirring until the sugar and butter are fully dissolved and the mixture turns a golden caramel color, about 5 minutes.
Remove the saucepan from heat and pour the hot caramel into the prepared dish, spreading it evenly with a spatula.
Let the caramel cool at room temperature for about 20 minutes until it’s firm but still pliable.
Once cooled, use a sharp knife to cut the caramel into bite-sized squares or rustic chunks, depending on your preference. If it’s too sticky, refrigerate for 10 minutes to make slicing easier.
Meanwhile, melt the dark chocolate in a microwave-safe bowl in short 30-second bursts, stirring until smooth and glossy.
Dip the top of each caramel piece into the melted chocolate, then place back on the parchment paper.
Immediately sprinkle a tiny pinch of sea salt on each chocolate-topped bite to enhance flavor.
Allow the chocolate to set for about 15 minutes at room temperature or refrigerate for quicker results. Once set, serve or store in an airtight container at room temperature for up to a week.
