This tart features a sweet shortbread pâte sucrée crust, a rich layer of silky chocolate mascarpone, and a piped topping of just-sweet-enough coffee mascarpone. Dusted with a layer of cocoa powder, it's basically a tiramisu tart!
6oz (1 cup, 170g)dark chocolatefinely chopped (I use a 72% cacao bar)
¼cup (50g)granulated sugar
2teaspoonvanilla extract
½teaspoonkosher salt
⅓cup (2.6 oz)heavy cream
¾cup (168g, 6 oz)mascarpone cheesecold, from refrigerator
COFFEE MASCARPONE TOPPING
1cup (224g, 8 oz)mascarpone cheesecold, from refrigerator
1cup (8 oz)heavy cream
¼cup (50g)granulated sugar
2 ½teaspoonsespresso powder
¼ - ⅓cup (25-33g)cocoa powderto dust on top
Instructions
PATE SUCREE
Into the bowl of a stand mixer fitted with the paddle attachment, add the butter, sugar and salt. Mix well to combine, and continue beating on medium high until mixture is pale and fluffy, about two minutes. Scrape down the sides of the bowl.
Add the flour and mix until just combined. Mixture will be coarse and grainy.
Add the egg yolk and mix for about 30 seconds. The dough should start to pull together into a ball.
Flatten the dough into a disc shape and wrap well with plastic wrap. Refrigerate for at least an hour.
Remove dough from refrigerator and let sit for 20-30 minutes to soften slightly. On a lightly floured surface, roll the dough out to a 10 inch diameter circle, making sure that it does not stick. Sprinkle a bit of flour on top of the dough and work surface as needed.
Carefully transfer dough to the 9 inch tart pan by rolling it over the rolling pin then lifting and unrolling it over the tin. Gently press the dough down into the pan while lifting up the sides, ensuring that no empty space remains between the dough and the pan. If any cracks or tears occur, patch with extra dough scraps. Trim the excess dough with a knife held parallel to your work surface to ensure the tart shell has a clean edge. Cover tart pan with plastic wrap and place in freezer to chill for 30+ minutes. (You can also stop at this stage if you need to break the steps up into multiple days).
Preheat oven to 350 degrees F (177 C, Gas number 4). Remove tart pan from freezer and cover the dough with a piece of parchment paper that you've crumpled up and then flattened back out. Fill with pie weights or dried beans (I use and reuse the latter) to keep the dough from bubbling up. Bake for 20 minutes and then carefully lift the weight-filled parchment from the pan. Return to the oven to bake an additional 10-15 minutes, until golden brown. Place on a baking rack to cool.
CHOCOLATE MASCARPONE FILLING
Combine chocolate, sugar, vanilla and salt in a medium mixing bowl. Heat heavy cream in microwave safe container in 30 second intervals until steaming. Pour cream over chocolate mixture and slowly whisk until all ingredients are blended and no lumps of chocolate remain. Add mascarpone and whisk until completely combined. Pour into cooled tart shell, smooth with an offset spatula if needed, and place in refrigerator to set.
COFFEE MASCARPONE TOPPING
Place mascarpone, heavy cream, and sugar into the bowl of a stand mixer fitted with the whisk attachment. In a very small bowl, mix espresso powder with ½ teaspoon water, stirring until fully dissolved. Add an additional ½ teaspoon water if necessary. Add espresso mixture to the mascarpone bowl.
Mix on medium speed just until firm peaks form and coffee mascarpone mixture holds its shape. Transfer mascarpone mixture to a 16 inch piping bag fitted with a large round tip (I used a Wilton 1A tip). Remove tart from fridge and use a toothpick to gently mark guidelines about every inch along the chocolate filling. Using the lines as reference, pipe rows of roughly quarter-sized circles of coffee mascarpone. Hold the bag straight up and down as you pipe. Continue until chocolate filling is completely covered with coffee mascarpone.
Place cocoa powder into a fine sieve or sifter. Gently tap the sieve while moving it over the tart to dust the top with cocoa. Adjust cocoa amount to your liking. I put a generous amount on top, completely covering the coffee mascarpone filling, and thought it made a good contrast to the sweeter elements.