Chocolate Hazelnut Tart

PreparationMake tart shell: Preheat oven to 350°F. Pulse hazelnuts with flour, sugar, and salt in a food processor until finely ground (be careful not to grind to a paste), then add butter and pulse until most of mixture resembles coarse meal with some roughly pea-size butter lumps. Add egg and vanilla and pulse just until mixture begins to clump. Press dough evenly over bottom and up side of tart pan and chill 10 minutes. Line tart shell with foil and fill with pie weights. Bake in middle of oven until pale golden along rim, about 15 minutes. Carefully remove foil and weights and bake shell until bottom and side are golden, about 10 minutes more. Cool in pan on a rack 10 minutes. Reduce oven temperature to 325°F. Make filling while shell cools: Put chopped chocolate in a bowl. Bring milk, sugar, and salt to a boil in a 1-quart saucepan over moderate heat, stirring, then pour milk over chocolate in bowl and let stand until chocolate is melted, about 1 minute. Whisk until smooth, then whisk in yolks and vanilla. Whisk in crème fraîche and pour into crust. Bake tart in middle of oven until just set, 20 to 25 minutes. Cool completely in pan on rack. Chill until firm, at least 1 hour, then bring to room temperature before serving.

PreparationMake tart shell: Preheat oven to 350°F. Pulse hazelnuts with flour, sugar, and salt in a food processor until finely ground (be careful not to grind to a paste), then add butter and pulse until most of mixture resembles coarse meal with some roughly pea-size butter lumps. Add egg and vanilla and pulse just until mixture begins to clump. Press dough evenly over bottom and up side of tart pan and chill 10 minutes. Line tart shell with foil and fill with pie weights. Bake in middle of oven until pale golden along rim, about 15 minutes. Carefully remove foil and weights and bake shell until bottom and side are golden, about 10 minutes more. Cool in pan on a rack 10 minutes. Reduce oven temperature to 325°F. Make filling while shell cools: Put chopped chocolate in a bowl. Bring milk, sugar, and salt to a boil in a 1-quart saucepan over moderate heat, stirring, then pour milk over chocolate in bowl and let stand until chocolate is melted, about 1 minute. Whisk until smooth, then whisk in yolks and vanilla. Whisk in crème fraîche and pour into crust. Bake tart in middle of oven until just set, 20 to 25 minutes. Cool completely in pan on rack. Chill until firm, at least 1 hour, then bring to room temperature before serving.