To prepare the crust: Preheat oven to 350 degrees. Grease the bottom and side of a 9" spring form pan.Using your food processor, turn vanilla wafers into fine crumbs. Place in bowl, add brown sugar, cocoa, melted butter and coffee extract. Combine with a fork until crumbs are all moistened. Press into the bottom and about 2 inches up the sides spring form pan. Bake for 7 minutes. Remove and set aside to cool.
To prepare the filling: In your mixer, beat cream cheese and sugar until smooth. Mix in sour cream, vanilla and coffee mixture until smooth. mix in eggs until blended. Fold in chopped candies. Pour into crust. Bake for 55-60 minutes or until center is almost set. Cool for 10 minutes, before carefully running a knife around the edge of the pan. Loosen cheesecake from spring form pan. Place in the refrigerator for a couple of hours.
To prepare the topping: Combine the sour cream, sugar and vanilla in a small bowl. Spread over the top of the cooled cheesecake. Top with crushed chocolate candies.