Name: Chocolate-Hazelnut Cake
Total time: 4 h 30 min
Ingredients: 8 tablespoons unsalted butter , softened, plus additional butter for the pan; 6 ounces (170 grams) semisweet or bittersweet chocolate; 1 1/3 cups hazelnuts , toasted, skinned, and toasted again; 1 cup (7 ounces/198 grams) sugar; 2 tablespoons unbleached all-purpose flour; 5 large eggs , separated, plus 1 large yolk; 1/4 teaspoon salt; Confectioners' sugar

Why This Recipe Works

The technique for our chocolate-hazelnut cake recipe was straightforward: In a mixer, we creamed the butter and sugar and added egg yolks, followed by melted chocolate and ground hazelnuts. We then whipped egg whites and folded them in, transferred the batter to a springform pan (for easy removal after baking), and slipped the pan into the oven. After several rounds of testing on our chocolate-hazelnut cake, we noted that the texture and crumb of the cake was largely determined by the quantity and texture of the nuts. We preferred the more refined texture of the cake made with toasted finely ground nuts, ground in a food processor along with some sugar to prevent the nuts from clumping.

Before You Begin

Serve with lightly sweetened whipped cream.

Instructions

Adjust an oven rack to the middle position and heat the oven to 350 degrees. Generously grease a 9-inch springform pan.

Place the chocolate in a medium heatproof bowl set over a pan of simmering water. Melt the chocolate, stirring occasionally to speed the process. Remove the bowl from the heat and cool to room temperature.

Place the hazelnuts, ¼ cup of the sugar, and the flour in a food processor fitted with a steel blade. Pulse repeatedly until the nuts are finely ground.

Beat the 8 tablespoons butter with a handheld mixer or standing mixer at medium speed until fluffy, about 2 minutes. Gradually add the remaining 3/4 cup sugar, beating until creamy, 2 to 3 minutes. Add the 6 egg yolks one at a time, beating well after each addition. Add the cooled choclate and beat just until blended in. Stir in the ground hazelnuts.

Put the 5 egg whites and the salt in a large, clean bowl and beat with an electric mixer until they form stiff peaks. With a rubber spatula, fold in one-third of the whites to the chocolate-nut mixture. Carefully fold in the remaining whites in two batches, taking care not to deflate the batter. Pour the batter into prepared pan.

Bake until a toothpick or thin skewer inserted halfway between the center and the outer rim of the cake comes out clean, 45 to 50 minutes. (The center of the cake will still be moist.) Remove the pan from the oven and cool completely on a wire rack, about 3 hours. (The cake can be wrapped in plastic and refrigerated for several days.) Just before serving, dust with confectioners’ sugar. Cut the cake into wedges and serve with whipped cream, if desired.