Chocolate Mousse Tart
Every so often I get a certain dessert idea into my head and start scribbling down possibilities on a piece of paper. No, I don’t run to my computer to type. I find that writing things down on paper takes longer and gives me enough of a window that specifics start to gel allowing the recipe to take shape.
The idea I had last week was for a chocolate mousse served in a shortbread-like tart shell. I didn’t want a pie, I wanted a tart. And a tart shell is very different from a pie crust.
I began with the crust and decided to add sugar both for crunch and a touch of sweetness. Sugary crusts can be temperamental. Often they like to fall apart during rolling or show faint lines of cracking after they’re baked. Adding just enough, but not too much, sugar makes the chilled dough easy to roll. The trick here is to have the dough just cold enough but not too cold. Cold enough means that the dough is malleable but not so firm that it falls apart when you try to roll it. And even if the dough does fall apart, this tart dough—unlike a pie dough—will not get tough when you rework it into a disk and begin rolling it again. Neat, eh? So don’t worry!
Here’s what the “dough” looks like after creaming the butter with the sugar and beating in the egg.
After adding the flour and mixing briefly, the dough gathers into a mass on the flat beater. the dough is ready to be shaped.
You shape the dough into a disk and refrigerate it for about 30 minutes, just to firm it up a bit. Then it’s ready to roll.
Once you’ve rolled the dough and fit it into the tart pan (see recipe), if the dough breaks at any point, you can “heal” it simply by pressing the pieces together. The thing to remember when fitting the dough into the tart pan is to make the thickness as even as possible on the sides and bottom. And you don’t have to rush the process.
Once the dough is shaped, cover it loosely with plastic and refrigerate to firm it up. Then it’s ready to bake. You don’t need to line the pastry shell with foil and pie weights or beans, something I always do when baking a pie crust.
The baked crust is evenly browned and does not puff up during baking.
The mousse filling is light and airy and contrasts perfectly with the tart crust. Although I just use vanilla as the flavoring, feel free to use a liqueur such as Kahlua, Tia Maria, Grand Marnier, or Cointreau, or any other flavoring that pairs well with chocolate.
The chocolate mousse and whipped cream are ready to fold together for the light-textured filling.
You can make the crust a day ahead and leave it at room temperature, loosely wrapped. You can even fill the crust with the mousse and refrigerate it overnight. On serving day, just make the topping and decorate the pie with the grated chocolate.
The completed tart cut and ready to serve. Note the airiness of the filling.
Chocolate Mousse Tart
You’ll need a 9- to 10-inch tart pan with fluted sides and a removable bottom.
1 stick (4 ounces) unsalted butter, cut into pieces and slightly softened
¼ cup granulated sugar
1/4 teaspoon salt
1 large egg, lightly beaten
1 teaspoon vanilla extract
7 ounces (1 1/3 cups) unbleached all-purpose flour, measured by dipping dry measuring cups into flour container, filling to overflowing, and sweeping off excess with a straight edge
Chocolate Mousse Filling
8 ounces bittersweet chocolate, chopped
5 tablespoons water
1 tablespoon pure vanilla extract
4 large eggs, separated
1/4 teaspoon salt
¼ cup granulated sugar
¾ cup heavy cream
1 cup heavy cream
2 tablespoons confectioners’ sugar
½ teaspoon vanilla extract
Grated bittersweet chocolate for decorating
Making the Pastry
- Put the butter into a medium-size bowl and add the sugar and salt. Beat with an electric mixer on medium speed until smooth and creamy, 1 to 2 minutes. If you have a stand mixer with a flat beater, use it to do the job. Scrape the bowl and beater.
- Combine the egg and vanilla in a small cup. Add to the butter and sugar gradually while beating on low; beat until each addition is incorporated before adding the next. When all the egg has been added, increase the speed to medium and beat 1 to 2 minutes more, or until smooth.
- Add the flour and beat on low until the flour is completely incorporated and the dough gathers into several large masses. Dough may be slightly sticky. Turn the dough out onto a lightly floured surface and press together to form one lump. Knead briefly—just a few strokes—incorporating as little flour as possible, until the dough is completely smooth.
- Flatten the dough into a ½-inch-thick disk, wrap securely in plastic, and refrigerate for 30 minutes to firm the dough a bit.
Shaping and Baking the Crust
- Roll the dough on a lightly floured surface to a circle measuring 12- to 13-inches in diameter. Fold the dough in half and center it over the tart pan. Set the dough down gently onto the rim of the pan, and carefully unfold the dough. Lift an edge of the dough and push some of the excess down into the pan making the sides of the dough a tad thicker than the bottom. Repeat as you work your way all around the pan. Run a rolling pin across the tart pan to cut away excess dough. With your fingertips, smooth the dough all around the sides and bottom. Cover with plastic wrap and refrigerate 30 minutes.
- Meanwhile, adjust an oven rack to the lower third position and preheat the oven to 375 degrees. Remove plastic from the chilled dough and prick the bottom all over with a fork. Don’t be concerned if the fork doesn’t penetrate the chilled dough completely. Set the tart pan on a baking sheet and put into the oven.
- Bake about 20 minutes total, until the tart shell is completely cooked and golden brown with the edges a bit darker than the bottom. Check the shell after 10 minutes of baking to see if it is puffing up. If it is, remove the pan from the oven and re-prick the bottom of the pastry with a fork. Return to the oven to finish baking. When baked, remove from the oven and cool completely.
- To remove the tart shell from the pan, set the pan onto a surface slightly smaller than the bottom of the pan, such as a can or small bowl, and the sides of the pan should fall away from the tart. Use a large metal spatula to release the shell from the pan bottom and slide it onto a dessert platter.
To Make the Filling
- Melt the chocolate with the water in a medium bowl set over a larger bowl with simmering water. Do not allow the water to reach the bottom of the bowl. Stir occasionally with a whisk until the chocolate is completely melted and smooth. Remove the bowl from above the water and whisk in the egg yolks one at a time. Add the vanilla and whisk until smooth.
- In a clean bowl with clean beaters, whip the egg whites with the salt on medium-low speed until foamy. Increase the speed to medium and continue beating until the whites form soft peaks that droop at their tips when the beater is raised. Sprinkle in the sugar in a thin stream and continue beating until the whites are shiny and form stiff, slightly quavering peaks, when the beater is raised.
- Stir about one-fourth of the whites into the chocolate to lighten it, then fold in the remaining whites carefully and gently until no streaks of white show. Whip the 3/4 cup cream until it holds a soft shape, not until it is stiff. Fold it gently into the mousse. Transfer the mousse to the cooled tart shell set on a dessert platter. If all of the filling won’t fit, refrigerate the tart for 15 minutes to allow the filling to set a bit, but keep the remaining filling at room temperature. Once the filling in the tart shell is slightly firm, you can spoon the remaining filling on top. Refrigerate for 3 to 4 hours.
To Make the Topping
- In a chilled bowl with chilled beaters, whip the cream, sugar, and vanilla until the cream is stiff enough to hold its shape and is spreadable. Spread the cream over the filling and sprinkle with the grated chocolate. Refrigerate until serving time. Cut into portions with a sharp knife. This tart keeps well, refrigerated, for 3 or 4 days.
Makes 10 to 12 servings.