Once the bars have fully cooled, begin the caramel. In a small saucepan, melt the brown sugar and unsalted butter over medium heat. Stir continuously as the sugar dissolves and the mixture becomes smooth, preventing it from sticking or burning on the bottom of the pot.
Slowly pour in the heavy cream, taking care as the mixture may bubble. Add a pinch of salt and let the caramel simmer for 2–3 minutes until it thickens slightly. It should coat the spoon lightly without being overly thick; it will continue to firm as it cools.
Pour the warm caramel evenly over the cooled cheesecake layer, tilting the pan gently if needed to encourage it to spread smoothly across the top. Place the pan in the refrigerator and chill for at least 2 hours to allow the cheesecake and caramel layers to fully set.
Once chilled, lift the dessert out using the parchment overhang and slice it into 12 squares. For clean, sharp edges that show off each layer, use a hot knife and wipe it between cuts. Serve chilled with an extra drizzle of caramel if desired.
Tips
Use a hot knife to slice clean pieces without smudging the layers.
Chill overnight for the best flavor and a firm, well-defined texture.
