Preparation Combine milk and coffee powder in heavy medium saucepan. Stir over medium heat until coffee dissolves. Add marshmallows; stir until marshmallows melt and mixture is smooth, about 3 minutes. Pour into large bowl. Let stand at room temperature until cool but not set, whisking occasionally, about 1 hour. Beat cream and vanilla in medium bowl until stiff peaks form. Fold 2 1/2 cup whipped cream into coffee mixture. Fold remaining cream into coffee mixture in 2 additions. Stir chocolate in top of double boiler over simmering water until melted. Turn off heat. Pour melted chocolate into large bowl, reserving 1 tablespoon in top of double boiler for Cool chocolate to lukewarm. Whisk 1 cup coffee mousse into chocolate in bowl. Gently fold 1 more cup coffee mousse into chocolate mixture. Pour remaining coffee mousse over. Using large spatula, gently swirl to create marbled effect. Spoon mousse into 6 goblets. Rewarm reserved 1 tablespoon chocolate in top of double boiler over simmering water if necessary. Drizzle chocolate over each dessert. Cover and chill overnight.
Preparation Combine milk and coffee powder in heavy medium saucepan. Stir over medium heat until coffee dissolves. Add marshmallows; stir until marshmallows melt and mixture is smooth, about 3 minutes. Pour into large bowl. Let stand at room temperature until cool but not set, whisking occasionally, about 1 hour. Beat cream and vanilla in medium bowl until stiff peaks form. Fold 2 1/2 cup whipped cream into coffee mixture. Fold remaining cream into coffee mixture in 2 additions. Stir chocolate in top of double boiler over simmering water until melted. Turn off heat. Pour melted chocolate into large bowl, reserving 1 tablespoon in top of double boiler for Cool chocolate to lukewarm. Whisk 1 cup coffee mousse into chocolate in bowl. Gently fold 1 more cup coffee mousse into chocolate mixture. Pour remaining coffee mousse over. Using large spatula, gently swirl to create marbled effect. Spoon mousse into 6 goblets. Rewarm reserved 1 tablespoon chocolate in top of double boiler over simmering water if necessary. Drizzle chocolate over each dessert. Cover and chill overnight.