!Adapted from The Silver Palate Cookbook

8 ounces white chocolate, chopped

1/2 cup (4 ounces or 1 stick) butter

6 eggs, separated, at room temperature

1 cup powdered sugar

1/2 cup Frangelico (hazelnut) liqueur

2 cups heavy cream, cold

1/8 teaspoon cream of tartar

Gently microwave white chocolate and butter in a microwave-safe bowl, stopping and stirring at 30-second increments till melted and smooth.
Whisk the yolks, sugar, and Frangelico in the bowl for the top of the double boiler (or a bowl large enough to sit over a pan of simmering water) it thickens. Set it over the double boiler, with just simmering water, and cook until very thick, about 3 minutes, whisking constantly. Remove from heat and set aside.
Whisk the white chocolate into the egg mixture.
In another bowl, beat the heavy cream over high speed until stiff peaks form.
Using a mixer with the whisk attachment and a very clean bowl (any oil or grease will prevent whites from whipping properly), with whisk attachment, beat the egg whites and cream of tartar till stiff but not dry.
Gently fold the cream and egg whites into the white chocolate mixture. Scoop mixture into pretty serving dishes. Refrigerate for at least 3 hours to set before serving. Garnish with berries or chocolate shavings/curls if desired.