Stir instant coffee into chilled coffee to dissolve. Sprinkle gelatin into chilled coffee and let soften for about 1 minute. Stir gelatin mixture into condensed milk in a small pot. Stir over low heat until gelatin dissolves. Stir in vanilla and add ½ cup of gelatin base to a small bowl and remaining gelatin base to a large bowl. Add melted chocolate to large bowl and stir to combine. Cool both mixtures to room temperature.
Whip cream to soft peaks. Fold 1 cup of whipped cream into mixture in small bowl in 2 additions to make the cappuccino mousse layer. Fold 3 cups of whipped cream into chocolate mixture in large bowl in 2 additions to make the mocha mousse layer.
Spoon the mocha mousse to fill serving glasses ¾’s full. Top each serving glass with a layer of cappuccino mousse. (The amount of servings depends on size of glasses or cups used.) Chill at least 2 hours.
Garnish mousses with a dollop of whipped and dust with cocoa powder or cinnamon just before serving.