For the Crust:
1/2 batch chocolate cookie tart (recipe below)
1 batch soft caramel filling

For the Truffles:
3/4 cup heavy cream
2 tablespoons unsalted butter
Pinch of salt
1 tablespoon corn syrup (optional)
8 ounces bittersweet chocolate, finely chopped
1/4 cup cocoa powder

For assembly:
1/2 teaspoon large-grain fleur de sel (sea salt)

For the Chocolate cookie tart crust:
2 eggs
2 tablespoons sweetened condensed milk
2 tablespoons brewed coffee, cooled
1 1/2 cups all-purpose flour, cold
1/2 cup cocoa powder
3/4 cup sugar
1 tablespoon instant espresso powder
1 teaspoon salt
3/4 cup unsalted butter, cut into small pieces and chilled

For the Soft caramel filling:
1 cup sugar
3/4 cup corn syrup
1 teaspoon salt
2 tablespoons unsalted butter
⅓ cup heavy cream
1 teaspoon vanilla bean paste