To round out chocolate flavor, we add a moderate amount of butter to a rich, custard-style filling baked in an almond-laced pâte sucrée dough. We bake the custard at a gentle 250 degrees to ensure a silky-smooth texture.
- 3tablespoons heavy cream
- 1tablespoon light corn syrup
- 2ounces bittersweet chocolate, chopped fine
- 1tablespoon hot water
- 1. FOR THE CRUST: Beat egg yolk and cream together in small bowl. Process almonds and sugar in food processor until nuts are finely ground, 15 to 20 seconds. Add flour and salt; pulse to combine, about 10 pulses. Scatter butter over flour mixture; pulse to cut butter into flour until mixture resembles coarse meal, about 15 pulses. With processor running, add egg yolk mixture and process until dough forms ball, about 10 seconds. Transfer dough to large sheet of plastic wrap and press into 6-inch disk; wrap dough in plastic and refrigerate until firm but malleable, about 30 minutes. (Dough can be refrigerated for up to 3 days; before using, let stand at room temperature until malleable but still cool.)
- 2. Roll out dough between 2 large sheets of plastic into 11-inch round about 3/8 inch thick. (If dough becomes too soft and sticky to work with, slip it onto baking sheet and refrigerate until workable.) Place dough round (still in plastic) on baking sheet and refrigerate until firm but pliable, about 15 minutes.
- 3. Adjust oven rack to middle position and heat oven to 375 degrees. Spray 9-inch tart pan with removable bottom with vegetable oil spray. Keeping dough on sheet, remove top layer of plastic. Invert tart pan (with bottom) on top of dough round. Press on tart pan to cut dough. Using 2 hands, pick up sheet and tart pan and carefully invert both, setting tart pan right side up. Remove sheet and peel off plastic; reserve plastic. Roll over edges of tart pan with rolling pin to cut dough. Gently ease and press dough into bottom of pan, reserving scraps. Roll dough scraps into ¾-inch-diameter rope (various lengths are OK). Line edge of tart pan with rope(s) and gently press into fluted sides. Line tart pan with reserved plastic and, using measuring cup, gently press and smooth dough to even thickness (sides should be about ¼ inch thick). Using paring knife, trim any excess dough above rim of tart; discard scraps. Freeze dough-lined pan until firm, 20 to 30 minutes.
- 4. Set dough-lined pan on baking sheet. Spray 12-inch square of aluminum foil with oil spray and press foil, sprayed side down, into pan; fill with 2 cups pie weights. Bake until dough is dry and light golden brown, about 25 minutes, rotating pan halfway through baking. Carefully remove foil and weights and continue to bake until pastry is rich golden brown and fragrant, 8 to 10 minutes longer. Let cool completely on sheet on wire rack.
- 5. FOR THE FILLING: Heat oven to 250 degrees. Bring cream, espresso powder, and salt to simmer in small saucepan over medium heat, stirring once or twice to dissolve espresso powder and salt. Meanwhile, place chocolate in large heatproof bowl. Pour simmering cream mixture over chocolate, cover, and let stand for 5 minutes to allow chocolate to soften. Using whisk, stir mixture slowly and gently (so as not to incorporate air) until homogeneous. Add butter and continue to whisk gently until fully incorporated. Pour eggs through fine-mesh strainer into chocolate mixture; whisk slowly until mixture is homogeneous and glossy. Pour filling into tart crust and shake gently from side to side to distribute and smooth surface; pop any large bubbles with toothpick or skewer. Bake tart, on baking sheet, until outer edge of filling is just set and very faint cracks appear on surface, 30 to 35 minutes; filling will still be very wobbly. Let cool completely on sheet on wire rack. Refrigerate, uncovered, until filling is chilled and set, at least 3 hours or up to 18 hours.
- 6. FOR THE GLAZE: Thirty minutes before glazing, remove tart from refrigerator. Bring cream and corn syrup to simmer in small saucepan over medium heat; stir once or twice to combine. Remove pan from heat, add chocolate, and cover. Let stand for 5 minutes to allow chocolate to soften. Whisk gently (so as not to incorporate air) until mixture is smooth, then whisk in hot water until glaze is homogeneous, shiny, and pourable. Working quickly, pour glaze onto center of tart. To distribute glaze, tilt tart and allow glaze to run to edge. (Spreading glaze with spatula will leave marks on surface.) Pop any large bubbles with toothpick or skewer. Let stand for at least 1 hour or up to 3 hours.
- 7. Remove outer ring from tart pan. Insert thin bladed metal spatula between crust and pan bottom to loosen tart; slide tart onto serving platter. Cut into wedges and serve.