Prepare the Pan: Line a 9×13 pan with parchment paper, leaving extra on the sides for easy lifting.
Make the Caramel: In a large saucepan, combine brown sugar, butter, sweetened condensed milk, corn syrup, vanilla, molasses, and salt. Cook over medium-low, stirring until the sugar dissolves (about 12–15 minutes).
Cook to Temperature: Attach a candy thermometer. Increase heat to medium-high and continue stirring until the caramel reaches 244°F (soft-firm chewy stage), about 12–15 minutes.
Cool & Set: Pour caramel into the prepared pan, spread evenly, and let cool completely until firm.
Cut into Squares: Lift caramel out using parchment and cut into bite-size squares.
Dip in Chocolate: Melt chocolate in 20-second microwave intervals, stirring until smooth. Dip each caramel, let excess drip off, place on parchment, and sprinkle with flaky sea salt before the chocolate sets.