Heat oven to 450°F. Place pie crust in 9-inch pie pan or 10-inch tart pan with removable bottom as directed on box for One-Crust Filled Pie. Bake 9 to 11 minutes or until lightly browned. Cool.
In small saucepan, melt 6 oz chocolate and the butter over low heat, stirring constantly; remove from heat. In small bowl, beat powdered sugar and cream cheese. Stir in melted chocolate mixture; beat until smooth. Add 1 cup of the cherry pie filling; blend gently. Set aside remaining pie filling. Spread mixture evenly into cooled crust. Refrigerate 1 hour.
In small bowl, mix topping ingredients. Spread evenly over cooled chocolate layer. Spoon remaining cherry pie filling in a band around outer edge of tart. Refrigerate until serving time.