1. Heat oven to 375°F. Melt chocolate according to package directions; cool.
2. Beat cream cheese in medium bowl until fluffy; gradually add sugar, beating until well blended. Add eggs; beat well. Beat in vanilla and melted chocolate until completely blended. Spoon into crust.
3. Bake 20 minutes or just until center is almost set. Remove from oven; cool 1 hour.
4. Spread SOUR CREAM TOPPING over top of pie. Bake 10 minutes or just until set. Cool to room temperature. Cover; refrigerate until firm. Just before serving, spread cherry pie filling over top of pie. Refrigerate leftover pie. 8 servings.
TOPPING: Stir together 1 cup dairy sour cream, 1/3 cup sugar and 1/2 teaspoon vanilla extract in small bowl.