Ethereal mousse, made by folding chocolate ganache into sweetened whipped cream, is firmly rooted in a humble cookie-crumb-and-nut crust. Candied hazelnuts are sprinkled on top.

　　

Ingredients

makes one 9-inch tart

　　

For the Crust

6 graham cracker sheets (about 3 ounces)

　　1/2 cup toasted hazelnuts (see page 343)

　　1/4 teaspoon coarse salt

　　2 tablespoons granulated sugar

　　4 tablespoons unsalted butter, melted and cooled

　　

For the Topping

1/3 cup toasted hazelnuts (see page 343)

　　1/4 cup granulated sugar

　　1/4 teaspoon coarse salt

　　1/4 cup water

　　

For the Filling

1 3/4 cups heavy cream

　　5 ounces bittersweet chocolate (preferably 61 percent cacao), coarsely chopped

　　2 tablespoons confectioners’ sugar

　　

Step 1

Make the crust: Preheat oven to 350°F. In a food processor, combine graham crackers, hazelnuts, salt, and granulated sugar; process until fine crumbs form. With machine running, slowly pour butter through feed tube and process until combined. Press crumbs into bottom and up sides of a 9-inch fluted tart pan with a removable bottom. Bake until crust is golden brown and fragrant, 12 to 14 minutes. Let cool completely in pan on a wire rack.

　　

Step 2

Meanwhile, make the topping: In a small saucepan, combine hazelnuts, granulated sugar, salt, and water. Bring to a boil; cook 1 minute. Drain hazelnuts and spread in a single layer on a parchment-lined rimmed baking sheet. Bake until nuts are toasted and shiny, 15 minutes. Let cool completely.

　　

Step 3

Make the filling: In a medium saucepan, bring 3/4 cup cream to a simmer; remove from heat and add chocolate. Let stand 5 minutes; whisk to combine, then let cool to room temperature. In a large chilled bowl, whip remaining 1 cup cream with the confectioners’ sugar until stiff peaks form. Gently fold in chocolate mixture until combined. Pour filling into baked, cooled crust and refrigerate until completely set, 2 hours or, wrapped tightly with plastic, up to 2 days. Top tart with candied hazelnuts before serving.

　　Martha Stewart's New Pies and Tarts