1 (8 1/2 oz.) chocolate wafers, crushed
1/3 c. melted butter
1/4 c. sugar
3 (8 oz.) pkg. cream cheese, softened
3 tbsp. flour
4 oz. sweet chocolate, melted and cooled
1 c. sugar
3 eggs
2 tbsp. half and half
2 tsp. vanilla
1/2 c. sour cream
1/2 tsp. vanilla

Combine first 3 ingredients in bowl; mix well. Press over bottom and sides of 9 inch springform pan. Beat cream cheese, flour, chocolate and 1 cup sugar in bowl until light and fluffy. Add eggs one at a time, beating well after each addition. Blend in half and half and 2 teaspoons vanilla.

Pour into prepared pan. Bake at 400 degrees for 10 minutes. Reduce temperature to 300 degrees. Bake 55 minutes longer. Cool for 10 minutes. Remove side of pan. Spread mixture of sour cream and 1/2 teaspoon vanilla over cooled cheesecake.