Combine crumbs, sugar, cocoa, and butter; press firmly on bottom and up side of 9-inch pie plate.
In mixing bowl, beat cheese until fluffy. Gradually beat in milk then add melted chocolate chips. Add eggs and vanilla; mix well. Pour into prepared crust.
Bake 30 to 35 minutes or until center is set. Cool. Chill thoroughly. Garnish as desired with chocolate shavings and whipped cream. Refrigerate leftovers.