Active Time

　　30 min

　　Total Time

　　3 hr (includes cooling)

　　Torta di Cioccolata al Forno con Vaniglia e Noccio

　　For this sophisticated cake, which will thrill any fan of bittersweet chocolate, Ferrigno took inspiration from a favorite Perugian café called Bar Sandri—Perugia being, as she puts it, the "firm historical chocolate capital" of Italy. And inspiration was all she could take: She requested the recipe from the chef several times, but he wouldn't divulge it. Desperate, she played around with the ingredients until she came up with something that tasted right.

　　

Ingredients

Makes 6 to 10 servings

　　

For crust:

1/4 pound wheatmeal crackers finely crushed (about 1 cup)

　　1 ounce fine-quality bittersweet chocolate (no more than 60% cacao if marked), grated

　　1/2 stick unsalted butter, melted

　　

For filling:

1/2 pound fine-quality bittersweet chocolate (no more than 60% cacao if marked), chopped

　　1 stick unsalted butter, cut into pieces

　　1 pound 2 ounce cream cheese, at room temperature

　　1/2 cup sour cream

　　1/4 teaspoon pure vanilla extract

　　2 large eggs

　　2/3 cup superfine granulated sugar

　　1 cup hazelnuts (4 1/2 ounces), toasted loose skins rubbed off in a kitchen towel while still warm, and nuts chopped

　　

Equipment:

Equipment: a 10-inch springform pan

　　Accompaniment: lightly sweetened whipped cream

　　

Make crust:

Step 1

Combine all ingredients, then press onto bottom of springform pan.

　　

Make filling and bake cheesecake:

Step 2

Preheat oven to 325°F with rack in middle.

　　

Step 3

Melt chocolate with butter, then remove from heat and whisk in cream cheese until smooth. Whisk in sour cream and vanilla.

　　

Step 4

Whisk together eggs and sugar in a large bowl until mixture has a mousse-like consistency, then stir in chocolate mixture and nuts.

　　

Step 5

Pour filling into crust and bake 1 1/2 hours. (Top will be slightly cracked.)

　　

Step 6

Cool to room temperature in pan on a rack, about 1 hour, then chill at least 1 hour. (Cake will sink slightly.)

　　Cooks' notes:

　　•Wheatmeal biscuits are British-style whole-wheat crackers. Look for Carr's (labeled "Whole Wheat Crackers" and found at most supermarkets) or McVitie's brand (found at some specialty foods shops).

　　•Chocolate hazelnut cheesecake can be chilled up to 1 day. Bring to room temperature before serving.