Join Carla in the Bon Appétit Test Kitchen as she makes a salted caramel-chocolate tart! You can use a 9\" or 10\" tart pan, but the layers will be thinner in the larger pan. We also found that Morton kosher salt won’t dissolve completely in the caramel filling, so use Diamond Crystal for the best results for this tart recipe. Then, a generous sprinkling of flaky sea salt before serving brings out the flavor of the chocolate and tempers the sweetness of the caramel.