INGREDIENTS FOR CRUST:INGREDIENTS FOR RASPBERRY SAUCE:
- 1 cup vanilla wafer crumbs
- 3 tablespoons unsalted butter, melted
- 6 ounces plus 2 ounces white chocolate, chopped
- 3/4 cup sugar
- 1/4 cup water
- 4 large egg whites
- 1/8 teaspoon cream of tartar
- 1-1/2 cups heavy whipping cream, chilled
- 1 tablespoon Grand Marnier
- 1 teaspoon vanilla extract
- 3 tablespoons chopped pistachios
- 2 cups fresh or frozen unsweetened raspberries
- 1/4 cup sugar
- 2 tablespoons Grand Marnier
Combine crumbs and butter. (Do not use food processor.) Press evenly into bottom of a 9-inch springform pan. Refrigerate.
Melt 6 ounces white chocolate in top of a double boiler, stirring until smooth. Cool slightly. Bring sugar and water to a boil in a small saucepan, stirring until sugar dissolves. Continue boiling, without stirring, until a candy thermometer reads 238 degrees (soft-ball stage). Beat egg whites and cream of tartar until soft peaks form. Gradually beat hot sugar syrup into egg whites. Continue beating until mixture is stiff and glossy, about 3 minutes. Fold in warm chocolate. Refrigerate chocolate mixture until cool, but not set, about 5 minutes. Whip cream, Grand Marnier, and vanilla in a large bowl until soft peaks form. Gently fold cream into chocolate mixture. Fold in remaining 2 ounces white chocolate. Pour mousse into prepared crust and smooth top. Freeze until firm, about 6 hours. Sprinkle with pistachios. Cover with plastic wrap and return to freezer.
Raspberry Sauce: Puree raspberries in a blender. Strain puree to remove seeds. Stir in sugar and Grand Marnier. Refrigerate sauce at least 1 hour.
Remove mousse cake from freezer just before serving. To serve, spoon sauce onto individual plates and place a slice of cake on each. (Both mousse cake and raspberry sauce can be prepared up to 3 days before serving.)