Preheat oven to 350°F.

Combine graham cracker crumbs, cocoa and granulated sugar in 9-inch pie plate. Stir in butter until moistened; press onto bottom and up side of pie plate.

Bake 8 to 10 minutes. Sprinkle 1/2 cup morsel over bottom of hot crust; let stand for 10 minutes or until all morsels are shiny. Spread chocolate over bottom and up side of crust. Cool to room temperature.

Microwave 2 cups morsels and 3/4 cup cream in large, uncovered, microwave-safe bowl on high (100 power) for 1 minute; stir. The morsels may retain some of their original shape. If necessary, microwave an additional 10 to 15 second intervals, stirring until morsels are melted. Cool to room temperature.

Beat remaining cream, powdered sugar and vanilla extract in chilled small mixer bowl until soft peaks form. Foldc2 cups whipped cream into chocolate mixture. Spoon into crustv; swirl top. Garnish with remaining whipped cream. Refrigerate until firm.

Microwave remaining 1/4 cup morsels in heavy-duty plastic bag on high (100 power) for about 30 seconds; knead until smooth. Cut tiny corner from bag; squeeze to drizzle chocolate over pie. Let stand a few minutes before serving.