For crust: Combine vanilla wafer crumbs, hazelnuts, sugar and melted butter in medium bowl and blend thoroughly. Pat mixture into bottom and sides of 20 cm springform pan. Refrigerate until firm, approx 30 minutes. Preheat oven to 300 degrees. Bake crust 15 minutes. Let cool completely. For Filling: Preheat oven to 350 degrees. Beat cream cheese at low speed in large bowl of electric mixer until smooth. Gradually beat in 1 cup sugar. Add eggs and creme de cocoa and blend until completely smooth, stopping once to scrape down sides of bowl. Pour into cooled crust. Bake until set, about 45-50 minutes. Let cool slightly. (Retain oven temperature at 350 degrees.) Combine sour cream and remaining sugar in medium bowl and blend well. Using rubber spatula, spread mixture over cheesecake to within 1 cm of edge. Bake 5 minutes. Preheat broiler. Run cheesecake under broiler, watching carefully, until top is lightly browned, about 1-2 minutes. Let cool. Refrigerate at least 5 hours, or overnight. Cheesecake can be refrigerated up to one week. Set the hazelnut in center of cake before serving. Serves 8-12. This taken from my mother's recipe collection, she got this one watching KTHV-11, Little Rock, on "Arkansas Today" Show, _Cooking with Don Bingham_, Sep 26, 1990.