Double Chocolate Tart

Ingredients

• For the crust:
• 1 1/2 cups all-purpose flour
• 3/4 cup confectioners' sugar
• 1/2 cup cocoa powder
• Pinch salt
• 9 tablespoons cold unsalted butter, cut into 1/4-inch pices
• 1 large egg yolk
• For the filling:
• 8 ounces semi-sweet chocolate, finely chopped
• 1 tablespoon confectioners' sugar
• 1/2 teaspoon instant espresso powder
• 3/4 cup whole milk
• 1/2 cup heavy cream
• 1 large egg, lightly beaten
• 1/2 teaspoon vanilla extract
• 2 pints chocolate ice cream to serve on side, optional

Directions

1. In the bowl of a food processor, combine the flour, confectioners' sugar, cocoa, and salt with roughly 3 pulses, each 1 second long. Add the butter and pulse again until the mixture looks like damp sand and you can’t see any pieces of butter, about 10 to 15 short pulses. Add the yolk and pulse just until the dough starts to gather together. Shape the dough in plastic wrap into a 5-inch disc, then refrigerate until firm, about 30 minutes.
2. While the dough chills, prepare the filling. Put the chocolate, sugar, and espresso powder in a medium bowl. Warm the milk and cream in a small saucepan until they reach a simmer, then pour the hot mixture over the chocolate and leave it alone for 5 minutes. Whisk until glossy and smooth, then whisk in the egg and vanilla. Set the filling aside.
3. Move an oven rack to the middle position and heat the oven to 350 degrees F. Roll the dough into a 13-inch circle between 2 pieces of parchment paper, between plastic wrap, or on a lightly floured surface. Carefully drape the dough over a rolling pin and unroll it into the tart pan. Press it into the base and up the sides, then freeze for 15 minutes. Line the tart shell gently with foil and add pie weights. Bake until the crust has set, about 25 minutes. Lift out the foil and weights carefully, then let the crust cool briefly on a wire rack for 10 minutes.
4. Pour the filling into the crust and bake until the edges are set but the center still has a little wobble, 15 to 20 minutes. Cool the tart on a wire rack for at least 45 minutes before serving.