1. Stir together sugar and gelatin in small saucepan; stir in milk. Let stand 2 minutes to soften gelatin. Cook over medium heat, stirring constantly, until mixture just begins to boil.
2. Remove from heat. Immediately add chocolate chips; stir until melted. Stir in liqueur; cool to room temperature.
3. Beat whipping cream in small bowl until stiff; gradually add chocolate mixture, folding gently just until blended. Spoon into serving dishes. Refrigerate. Garnish with sweetened whipped cream and raspberries, if desired. 2 servings.
VARIATION: For high-standing mousse, prepare collars for 2 parfait glasses. Tear strip of foil of sufficient length to go around top of each glass. Fold foil into fourths; butter lightly. Place buttered side in; tape to sides of glasses. Spoon mousse into glasses. (Mousse should come over top of glasses.) After mousse has set, carefully remove foil collar.