Chocolate Tart Dough
8 tablespoons (1 stick) unsalted butter, cut into 8 pieces
1 cup unbleached all-purpose flour
2 tablespoons plus 2 teaspoons unsweetened Dutch-processed cocoa powder
1/2 cup plus 2 tablespoons
1 large egg yolk
1) Let the butter sit at room temperature for 10 to 15 minutes. It should be malleable, but still cool.
2) Sift together the flour and cocoa powder.
3) Place the confectioners’ sugar in the bowl of a stand mixer or a medium mixing bowl. Add the butter and toss to coat. Using the paddle attachment, or a hand-held mixer, cream the sugar and butter at medium speed until the sugar is no longer visible. Scrape down the sides of the bowl. Add the egg yolk and beat until well blended. Scrape down the sides of the bowl again. Add half of the flour mixture and beat until the dough becomes crumbly. Stop the machine, add the remaining flour mixture, and beat until the dough forms a sticky mass. Shape the dough into a disk and wrap well in plastic. Refrigerate until firm, approximately 2 hours.
4) Dust a work surface with flour. Cut the chilled dough into 1-inch pieces. Using the heel of your hand, knead the pieces back together into a smooth disk. As you work, use a dough scraper to free the dough from the surface if necessary. Keeping the surface well dusted, roll the disk into a 10-inch log. If using flan rings, cut the log into 7 equal pieces; if using tart pans, cut it into 6 pieces. Refrigerate for 5 minutes.
5) If using flan rings, line a baking sheet with parchment paper and set seven 4-inch flan rings on it.
6) Dust the work surface and a rolling pin with flour. Using your fist, flatten one piece of dough into a 2- to 3-inch round. Lift it up off the work surface to dust underneath with flour. Using the rolling pin, roll the dough into a 5 1/2-inch round, or a 6-inch round if using tart pans, about 1/8 inch thick. With a pastry docker or a fork, prick holes all over the dough. If the dough is too soft to handle at this point, use a dough scraper to remove it to a small baking sheet and refrigerate it for 2 to 3 minutes before proceeding.)
7) Center the round of dough over a flan ring or a 4 3/4-inch fluted tart pan with a removable bottom. If using a tart pan, be careful that the sharp top edge does not tear the dough. With your thumbs on the inside and the tips of your fingers outside, run your hands around the ring or pan several times, easing the dough down into it. Speed does not matter, finesse does. Lower your thumbs to the inside bottom of the ring and press to form a right angle between the bottom and sides of the dough; if using a tart pan, press to form a clean angle without excess dough buildup. Keeping your thumbs on the inside of the ring or pan, again circle around it, applying light pressure to the sides; if you move the ring or pan around through your hands, the process will be easier. There should be at least a 1/2-inch rim of excess dough extending straight above the top edge. With a small knife, tilted upward, trim the excess dough flush with the top of the ring. Or, if using a tart pan, simply roll the rolling pin over the top to trim the excess. Repeat this process with the remaining pieces of dough. Refrigerate the scraps from each piece as you work, then knead them together and roll out another tart shell. If using tart pans, place them on a baking sheet.
8. Place the tart shells in the freezer for 30 minutes.
9) Position a rack in the center of the oven, and preheat the oven to 375 degrees F.
10) If you are partially baking the tart shells, bake for 8 to 10 minutes, until the interiors are dry and the pastry smell nicely of chocolate. If the bottoms of the shells puff up, tap down lightly with your fingers as often as necessary. Leave the tart shells on the baking sheet in their rings or pans.
If you are fully baking the tart shells, bake for 10 to 12 minutes, until the interiors are dry and there is a deep chocolate aroma. If using flan rings, remove the rings and, using a wide spatula, transfer the shells to a wire rack to cool. If using tart pans, let the shells cool completely in the pans on a rack before unmolding.
NOTE: To dust the work surface and rolling pin when working with chocolate dough, sift together 2 parts flour and 1 part cocoa powder and follow notes 1 through 6 below.INFO: