- 1 1/2 cups heavy cream, chilled
- 1/2 cup chocolate-hazelnut spread, heated until just pourable
- 1/2 cup sugar
- 3 eggs
- 1/4 teaspoon salt
- 1/2 cup chopped toasted hazelnuts
- 2 ounces bittersweet chocolate, shaved (optional)
Line a 5- by 9-inch loaf pan with plastic wrap, leaving a 2-inch overhang on all sides.
Beat whipping cream in a large bowl until soft peaks form. Fold in chocolate-hazelnut spread and beat again until mixture returns to soft peaks. Refrigerate while making the custard.
Whisk together sugar, eggs and salt in a bowl set over a pot of simmering water. Stir constantly with a heatproof spatula until the mixture reaches 160° F with an instant-read thermometer, about 4 minutes. Remove bowl from the simmering water. Using an electric mixture, beat until cool, thick and doubled in volume, about 6 minutes.
Fold in chilled whipped cream, chopped hazelnuts and shaved chocolate. Transfer mixture to the prepared loaf pan and smooth the top. Tap the loaf pan lightly on a work surface to remove air bubbles. Fold plastic wrap over the top to cover and freeze until firm, 8 hours to overnight.
Unfold plastic wrap from the top of the semifreddo and invert onto a platter; remove plastic wrap. Cut semifreddo into 1-inch slices using a large knife dipped in hot water.