A dreamy dark chocolate tart! This has Valentine's Day written all over it. I found the original recipe for this Chocolate Caramel Tart in a February 2002 issue of Martha Stewart Living during some recent spring cleaning.
Place the flour, cocoa, sugar, and salt in the bowl of a food processor, and pulse several times to combine. Add the butter, and pulse until the mixture resembles coarse meal, about 10 seconds. Add the egg yolks and vanilla, and process just until mixture begins to hold together, no more than 30 seconds.
Turn dough out onto a lightly floured surface, and form into a disk. Cover in plastic wrap; refrigerate for 30 minutes, or until ready to use.
Preheat oven to 350 degrees. Roll chocolate pâte sucrée ¼ inch thick, and fit into a 9-inch fluted tart pan with a removable bottom. Dock bottom of tart with a fork. Refrigerate the shell for 30 minutes.
Place the chopped pecans on a baking sheet, and toast until slightly darkened and fragrant, about 10 minutes; set aside.
Line tart shell with parchment paper, pressing into edges, and cover with dried beans or pie weights. Place on a baking sheet; bake for 20 minutes. Remove paper and beans, and continue baking until crust is golden, about 10 minutes. Transfer to a wire rack to cool completely.
Make the caramel by placing the sugar, salt and water in a small saucepan. Bring mixture to a boil over medium-high heat. Wash down the sides of the pan with a pastry brush dipped in water to prevent crystals from forming. Cook, gently swirling pan (do not stir), until the caramel is a rich amber color. Remove from heat, and add ½ cup cream, butter, and vanilla; stir until smooth. Pour mixture into chocolate tart shell.
Sprinkle the toasted pecans over the caramel, and place in the refrigerator while melting the chocolate.
Place chocolate in a medium heat-proof bowl. Bring remaining cup of cream to a boil in a small saucepan; pour over the chocolate. Let sit for 5 minutes; stir until completely smooth. Pour over caramel and nuts; return tart to refrigerator to chill for at least 1 hour.
To serve, dust the top of the tart with cocoa powder, if desired. Garnish with caramel-dipped pecans, if desired.