Chocolate Rum Raisin Cheesecake

Preparation : NOTE: Use a 10" springform pan. CRUST: In a medijum-sized bowl, combine the chocolate wafer crumbs, sugar, and butter. Blend well with fingers, fork, or pastry blender. Press or pat the mixture onto the bottom and sides of a well-buttered springform pan. Chill in the freezer of refrigerate for about 30 minutes. FILLING: In a large bowl, beat the cream cheese, sugar, and vanilla until smooth. Add the eggs, one at a time, making sure that the mixture is well beaten after each addition. Fold in the sour cream, again making sure that the mixture is smooth. In a small skillet, melt the butter, add the cocoa, and blend well. Add the cocoa mixture, the rum, and the raisins to the cheese mixture and mix until smooth and creamy. Pour into the chilled pan and bake in a preheated 375-degree oven for one hour, then turn off the oven, open the oven door one inch, and let the cake cook slowly for one hour. TOPPING: In a small mixing bowl, beat the sour cream, sugar, and cocoa until very smooth, then spread the mixture evenly over the top of the cake and bake in a preheated 350-degree oven for 5 minutes. Transfer the cake to a wire rack and allow to cool completely. After cooling, carefully remove the sides of the springform pan and refrigerate the cake for 2 to 3 hours. Transfer the cake to a serving dish and serve.