Ingredients
8ozbittersweet chocolate,preferably 61% percent cacao
1¼cupsheavy cream
2tbspground espresso beans,good-quality
1cupall purpose flour
¾tspsalt
unsweetened cocoa powder,dutch-process
½cupunsalted butter
¼cupsugar
¾tsppure vanilla extract
3tbspheavy cream
1½cupsmascarpone cheese
1large egg
Preparation
Put chocolate into a medium heatproof bowl, and set aside. Bring cream and espresso to a boil in a small pan. Pour through a fine sieve over the chocolate; discard solids. Let stand 2 minutes, then whisk until smooth.
Let cool to room temperature, 1 to 2 hours.
Sift flour, salt, and cocoa powder into a medium bowl; set aside. Put butter and sugar into the bowl of an electric mixer fitted with the paddle attachment; mix on medium speed for about 4 minutes until pale and fluffy.
Add egg and vanilla, and mix until combined, scraping down the sides of the bowl as needed. Reduce speed to low. Gradually add the flour mixture in 3 batches, alternating with the cream.
Shape dough into a thick rectangle; wrap in plastic. Refrigerate for about 30 minutes until cold.
Preheat oven to 350 degrees F. Roll out dough between 2 pieces of lightly floured parchment paper to a 16×6-inch rectangle, about ¼-inch thick. Press dough into a 14×4½-inch rectangular flan frame set on a baking sheet lined with parchment.
Trim dough flushes with the top edge. Prick all over the bottom of the shell with a fork. Bake for 18 to 20 minutes until firm. Transfer to a wire rack; let cool completely. Unmold.
Put the ganache into the bowl of an electric mixer fitted with the whisk attachment; beat on medium-high speed for about 4 minutes until soft peaks form. Transfer to a pastry bag fitted with a large star tip such as Ateco No. 828.
Smooth mascarpone cheese over the bottom of the tart shell with an offset spatula.
Pipe ganache rosettes, one next to the other, on top of mascarpone to cover.
Serve and enjoy.
