Chocolate Caramel Tart

Preheat oven to 350˚F. In a medium bowl, combine flour, 1/4 cup Dutch-process unsweetened cocoa powder, and 1/4 teaspoon kosher salt; set aside.

Using a handheld mixer in a large bowl, cream 10 tablespoons unsalted butter and confectioners' sugar until pale and fluffy. Mix in egg yolks and vanilla extract. Gradually mix in the reserved dry ingredients.

Transfer the dough to a 9-inch fluted tart pan with a removable bottom and press it evenly into the bottom and sides of the pan. Refrigerate for 30 minutes.

Prick the chilled tart shell all over with a fork. Bake until cooked through, about 20 minutes. Transfer to a wire rack and let cool completely.

To make the caramel: In a 1-quart saucepan, whisk together sugar, corn syrup, 1/4 teaspoon kosher salt, and 6 tablespoons water. Bring to a boil over medium heat and cook, without stirring, until a candy thermometer reads 340°F.

Remove the saucepan from heat and whisk in 6 tablespoons unsalted butter, 6 tablespoons heavy cream, and crème fraîche until smooth (the mixture will bubble up).

Pour the caramel into the cooled tart shell and let it cool slightly. Refrigerate until firm, 4–5 hours.

To make the ganache: Bring 1/2 cup heavy cream to a boil in a clean 1-quart saucepan over medium heat.

Place 4 ounces bittersweet chocolate, finely chopped, into a medium bowl. Pour the hot cream over the chocolate; let sit for 1 minute, then stir slowly with a rubber spatula until smooth.

Pour the ganache evenly over the caramel tart and refrigerate until set, 4–5 hours. Sprinkle with sea salt (optional, for serving), slice, and serve chilled.