The first time I visited Véronique Mauclerc’s bakery, I bought one of her pear and chocolate tartlets, and trotted on to the nearby Parc des Buttes-Chaumont. Once I’d climbed up a hill and found the ideal bench — in the semi-shade, amid the twitter of birds, with a faraway view of the Sacré-Cœur — I unwrapped my rustic-looking tartlet, took a bite, and beamed to myself.
I have eaten a fair amount of chocolate tarts in my life, but this one was a ravishing novelty: Its brittle, not-too-sweet crust held a fudgy and slightly leavened chocolate filling — rather than the classic layer of ganache — as if it couldn’t quite decide whether to be a tart or a cake. The following recipe is a re-creation of what I’ve come to think of as, quite simply, a tarte-gâteau.
1. Prepare the crust.
In a small bowl, beat together the egg yolk, water, salt and sugar, and set aside. Combine the flour and butter in the bowl of a food processor, and process at low speed for 10 seconds, until the mixture forms coarse crumbs. Pour in the egg yolk mixture all at once and process for a few more seconds, just until the dough comes together. If it is too dry, add a little more ice-cold water, 1 teaspoon at a time, until it reaches the right consistency.
Turn out on a lightly floured work surface and gather into a ball without kneading. Flatten the ball slightly, wrap in plastic, and refrigerate for 30 minutes, or up to a day (if you refrigerate it for more than an hour, let stand at room temperature for 10 minutes before using).
2. While the dough chills, poach the pears.
Combine 1 cup water, the sugar and the rum in a medium saucepan, and bring to a simmer over medium heat. Peel and core the pears. Cut each of them lengthwise into sixths, rather than quarters, in order to get twelve pieces total. Add the pears to the saucepan, bring back to a simmer, and cook for 4 minutes, until tender and slightly translucent. Lift the pears from the syrup cautiously with a slotted spoon, and set aside in a colander to drain.
Remove the dough from the refrigerator. Grease an 11- to 12-inch tart pan with a pat of butter (see note below). Working on a lightly floured work surface with a lightly floured rolling pin, roll the dough out into a 13- to 14-inch circle and line the pan with it, trimming off the excess dough.
Cover loosely with plastic wrap and refrigerate for 30 minutes; this will prevent the dough from shrinking as it bakes. Preheat the oven to 350° F and put the tart pan in the oven for 10 minutes.
While the crust blind-bakes, prepare the chocolate filling. Combine the flour, baking powder, and salt in a small bowl and set aside. Melt the chocolate and butter in a double boiler, or in a heatproof bowl set over a pan of simmering water, stirring regularly to combine. Transfer to a medium bowl, add the sugar, and stir with a wooden spoon. Add the egg and egg white, stirring well between each addition. Add the flour mixture and stir again until just combined. Remove the pan from the oven, but leave the heat on.
Pour the chocolate filling into the tart shell and even out the surface with a spatula. Arrange the pear pieces over the filling in a sun-ray pattern, the small ends pointing toward the center of the tart. Return to the oven and bake for 20 minutes, until the filling is just set at the center — it will continue to cook as it cools — and the crust is golden. Transfer to a rack and let cool completely before serving, on its own, with a scoop of yogurt gelato, or with a dollop of whipped cream.
Note: The recipe can be made in eight 4-inch (12-cm) tartlet molds, rather than one large tart. You should then cut each pear into fourths, rather than sixths, and reduce the baking time of the chocolate filling to 15 minutes.