PreparationMake crust: Blend flour, sugar, lemon eel and slat in processor 5 seconds. Add butter, yolk and vanilla and process until large moist clumps form. Gather dough into ball; knead briefly to combine well. Flatten into disk. Wrap in plastic; chill until firm enough to roll, about 30 minutes. Preheat oven to 400°F. Roll out dough between sheets of plastic wrap to 11- to 12-inch round. Peel off top sheet of plastic. Turn dough over; press into 9-inch-diameter tart pan with removable bottom. Peel off plastic. Fold in any excess dough, forming double-thick sides. Pierce crust all over with fork. Freeze 15 minutes. Bake crust 10 minutes. Using back side of fork, press crust flat if bottom bubbles. continue to bake until crust id golden, about 10 minutes (crust sides may shrink slightly.) Transfer to rack and cool. Make chocolate filling: Bring cream to boil in heavy small saucepan and whisk until smooth. Spread 1 cup chocolate filling in prepared crust. Refrigerate until firm, about 45 minutes. reserve remaining filling in saucepan. Make caramel filling: stir sugar and 1/3 cup water in heavy medium saucepan over low heat until sugar dissolves. Increase heat and boil until syrup is amber color, brushing down sides with wet pastry brush and swirling pan occasionally, about 8 minutes. Remove from heat. Add cream, butter, vanilla and salt (mixture will bubble up). Return pan to very low heat; stir until caramel is smooth and color deepens, about 5 minutes. Refrigerate uncovered until cold but not firm, about 20 minutes. Spoon caramel filling over chocolate filling. Pipe of drizzle reserved chocolate filling decoratively over cararmel (if chocolate is too firm to pour, warm slightly over low heat). Refrigerate tart until caramel is firm, at least 1 hour. (Can be made 2 days ahead. Cover keep chilled.)
PreparationMake crust: Blend flour, sugar, lemon eel and slat in processor 5 seconds. Add butter, yolk and vanilla and process until large moist clumps form. Gather dough into ball; knead briefly to combine well. Flatten into disk. Wrap in plastic; chill until firm enough to roll, about 30 minutes. Preheat oven to 400°F. Roll out dough between sheets of plastic wrap to 11- to 12-inch round. Peel off top sheet of plastic. Turn dough over; press into 9-inch-diameter tart pan with removable bottom. Peel off plastic. Fold in any excess dough, forming double-thick sides. Pierce crust all over with fork. Freeze 15 minutes. Bake crust 10 minutes. Using back side of fork, press crust flat if bottom bubbles. continue to bake until crust id golden, about 10 minutes (crust sides may shrink slightly.) Transfer to rack and cool. Make chocolate filling: Bring cream to boil in heavy small saucepan and whisk until smooth. Spread 1 cup chocolate filling in prepared crust. Refrigerate until firm, about 45 minutes. reserve remaining filling in saucepan. Make caramel filling: stir sugar and 1/3 cup water in heavy medium saucepan over low heat until sugar dissolves. Increase heat and boil until syrup is amber color, brushing down sides with wet pastry brush and swirling pan occasionally, about 8 minutes. Remove from heat. Add cream, butter, vanilla and salt (mixture will bubble up). Return pan to very low heat; stir until caramel is smooth and color deepens, about 5 minutes. Refrigerate uncovered until cold but not firm, about 20 minutes. Spoon caramel filling over chocolate filling. Pipe of drizzle reserved chocolate filling decoratively over cararmel (if chocolate is too firm to pour, warm slightly over low heat). Refrigerate tart until caramel is firm, at least 1 hour. (Can be made 2 days ahead. Cover keep chilled.)