1In small bowl, sprinkle gelatin over 1 tablespoon whipping cream; set aside to soften gelatin.
2In food processor, place strawberries and powdered sugar. Cover; process until smooth. Pour mixture into 1-quart saucepan; add softened gelatin. Cook over medium heat, beating with whisk occasionally, until mixture comes to a simmer and gelatin is dissolved. Remove from heat; cool 30 minutes.
3In small bowl, beat whipping cream with electric mixer on high speed until stiff peaks form. On low speed, beat strawberry mixture into whipped cream until blended.
4Place mousse in decorating bag fitted with small star tip. Pipe mousse into chocolate cups. Refrigerate until set, about 30 minutes, or up to 2 hours before serving. Garnish with fresh sliced strawberries, if desired.