Line a square baking dish with parchment paper and lightly grease.

In a medium saucepan, melt butter over medium heat. Add brown sugar, corn syrup, and heavy cream, whisking constantly.

Bring mixture to a boil, and cook until a candy thermometer reads 245°F (soft-ball stage), about 15–20 minutes.

Remove from heat and stir in vanilla extract and salt.

Pour half of the caramel into the prepared dish and let cool slightly.

For the vanilla cream filling, heat heavy cream until just warm and pour over white chocolate chips. Stir until smooth and creamy.

Spread the vanilla cream evenly over the slightly cooled caramel layer.

Pour remaining caramel over the vanilla cream, smoothing with a spatula. Let set at room temperature for at least 2 hours.

Cut into squares using a sharp knife and wrap individually in parchment paper if desired.