If you’ve never had a Pierre Hermé dessert, then I encourage you to make this tart, because it is typically Hermé-esque: its look is simple, its medley of textures is surprising, and its taste—the most important part—is sublime. At the base of the tart is a velvety coffee ganache that, unlike most ganaches, is made with white chocolate. When Pierre and I talked about the dessert, he explained that most tarts of this kind use a bittersweet chocolate ganache to which coffee is added and, “as good as that is, the tarts taste more of chocolate than coffee.” In other words, they’re mocha. But, as Pierre says, “white chocolate has wonderful texture, makes a good ganache, and carries the coffee flavor without adding much flavor of its own.” Pierre covers the cushion of ganache with a layer of featherlight ladyfingers (store-bought ladyfingers are ideal) soaked with another hit of coffee, and then lavishes the top with rosettes of coffee whipped cream. If you’re a lily gilder, you can add a shower of milk chocolate shavings.
A word on timing: Of course the crust can be made ahead, but the coffee cream must be made at least 6 hours, preferably 24 hours, in advance, and the finished tart should be refrigerated for at least 1 hour, all of which makes this the perfect party tart. In fact, the first time I made this tart, I prepared the ganache and finished the dessert (i.e., arranged and soaked the ladyfingers and whipped and piped the cream) while my husband was setting out the glasses and nibbles for aperitifs. Unlikely as it seems, with a little do-ahead work, this elegant tart is a quickie.
KEEPING: The crust, coffee cream, and chocolate shavings can be made ahead, and the finished tart can be kept in the refrigerator for up to 8 hours.
AN AMERICAN IN PARIS: Fans of Starbucks’ mochaccino might want to serve this tart surrounded by a drizzle of homemade or best-quality store-bought bittersweet chocolate sauce.
Total Timea day or more
Make Ahead RecipeYes
OccasionCooking for a date, Formal Dinner Party
Taste and Texturechocolatey, creamy, frothy, rich
Type of Dishchocolate dessert
- 1½ teaspoons powdered gelatin
- 2 tablespoons (30 grams) cold water
- 2 cups (500 grams) heavy cream
- 1½ tablespoons (20 grams) sugar
- 1/3 cup (12 grams) ground-for-espresso coffee, preferably French roast
- 10¾ ounces (300 grams) white chocolate, preferably an imported chocolate such as Valrhona Ivoire, finely chopped
- 1 cup (215 grams) heavy cream
- ¼ cup (20 grams) ground-for-espresso coffee, preferably French roast
- 1 fully baked 9-inch (24-cm) tart shell made with Sweet Tart Dough
- 10 to 12 store-bought ladyfinger biscuits, split lengthwise
- ½ cup (125 grams) very strong espresso, cooled
- Milk chocolate for shavings (optional)
TO MAKE THE COFFEE CREAM: It’s best to do this at least 6 hours ahead or, preferably, the day before you make the tart. Sprinkle the gelatin over the cold water and let it sit for 5 minutes, or until it is soft and spongy, then dissolve it by heating it for 15 seconds in a microwave oven (or do this stovetop); set aside.
Line a fine-mesh sieve with a quadruple thickness of damp cheesecloth. Bring the cream to the boil, add the coffee, and stir well, then pour the cream through the sieve; discard the coffee grounds. Wait for 1 minute, then stir the cream— if there’s any sediment, strain it again. Stir the sugar and dissolved gelatin into the cream and, once they are incorporated, put the cream into the refrigerator to chill for at least 6 hours, preferably 24.
TO MAKE THE GANACHE: Line a fine-mesh sieve with a quadruple thickness of damp cheesecloth. Warm the chocolate in a microwave oven (or over a pan of simmering water) just enough to melt it slightly. Pull the chocolate from the heat. Meanwhile, bring the cream to a full boil and stir in the coffee.
Pour the cream through the sieve over the white chocolate in two or three additions, stirring gently after each addition with a rubber spatula and only adding more cream when the previous amount is incorporated; discard the coffee grounds. Don’t worry if the ganache separates halfway through—it will come together once all the cream is stirred in. Once the ganache is smooth, it should be used immediately.
To finish: Pour the ganache into the tart shell. Cover the top of the ganache with the ladyfingers, placing the flat of each biscuit against the ganache and arranging the biscuits so that they cover the surface as completely as possible, a job that will require cutting a couple of biscuits to fit into small spaces. Using a pastry brush or a spoon, generously soak the biscuits with the cooled espresso.
Working by hand with a whisk, or using a mixer with a whisk attachment, beat the coffee cream until it holds firm peaks. Spoon the cream into a pastry bag fitted with a large star tip and pipe rosettes over the top of the tart, or spoon the cream over the tart and smooth it with a spatula. Refrigerate the tart, away from foods with strong odors, for at least 1 hour to set the ganache. (The tart can be kept in the refrigerator for up to 8 hours before serving. If the tart has been chilled for a long time, allow it to sit at room temperature for about 30 minutes before serving.)
If you’d like to top the tart with milk chocolate, hold the chocolate over a sheet of parchment or wax paper and, using a vegetable peeler, scrape chocolate shavings onto the paper. Refrigerate the shavings until ready to serve, and scatter them over the tart at the last minute.
2002 Dorie Greenspan