Beat the sugar, cream cheese and Kahlua on high for 3 minutes. Add eggs, one at a time, until blended. Pour mixture into pie crust. Bake @ 350 degrees for 25 minutes or until not quite set. Cool 1 hour at room temperature. Refrigerate at least 1 hour. Mix together sugar, sour cream and vanilla for topping. Spread on pie. Sprinkle with shaved chocolate. Refrigerate long enough to chill before serving.