Preparation Pour 2 tablespoons milk into small bowl. Sprinkle gelatin over and let soften 5 minutes. Whisk egg yolks and sugar in medium metal bowl to blend. Place over saucepan of simmering water (do not let bowl touch water). Whisk mixture over water until instant-read thermometer registers 160°F, about 3 minutes. Remove from heat. Add gelatin mixture to yolk mixture and whisk to dissolve gelatin. Place white chocolate in large bowl. Bring remaining 1/2 cup milk to simmer in heavy small saucepan. Pour hot milk over chocolate and whisk until chocolate is melted and smooth. Fold egg yolk mixture into chocolate mixture and let cool to room temperature. Whisk in 1/4 cup Grand Marnier. Whip cream to soft peaks. Fold whipped cream into Grand Marnier mixture. Divide mousse among 8 wineglasses. Cover and chill overnight. Whisk remaining 2 tablespoons Grand Marnier and orange marmalade in large bowl to blend. Add berries and toss gently to combine. Spoon blackberry topping over mousse in each glass and serve.