Bittersweet chocolate in the crust and topping is a dark and intense foil for creamy caramel in this rich pie, with toasted pecans lending a bit of texture.
Preheat the oven to 400°F. Lightly grease a 9" pie pan.
To make the crust: Whisk together the flour, cocoa, salt, and confectioners’ sugar. Work the butter into the dry ingredients; leave some of the butter in pea-sized lumps. Add 4 tablespoons of the water and the vanilla, mixing until the dough comes together. Add additional water as needed; the dough should be cohesive but not sticky. Wrap and chill the dough for 20 minutes.
After chilling, roll the dough into a 13" circle and place in the prepared pan; trim and flute the edges. Line the pan with foil or parchment and fill with pie weights. Bake for 15 minutes. Remove the pie from the oven, remove the pie weights and lining, and return to the oven for 15 minutes more, until set and you can smell the chocolate. Remove from the oven and set aside to cool.
To make the filling: Melt the caramel with the heavy cream and white chocolate over low heat (or in the microwave in 40-second bursts); stir until smooth. Pour into the crust and refrigerate for 1 hour to set.
To make the topping: Melt the chocolate with the cream and corn syrup over low heat or in the microwave, stirring until smooth. Remove the pie from the refrigerator and spread the topping over the caramel layer; sprinkle with the toasted pecans before the chocolate sets. Chill the pie until ready to serve; it will slice better when cold.
Store, covered, in the refrigerator for up to a week. Freeze for up to three months.
