Chocolate cheesecake

Filling:
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 Nonstick vegetables oil spray **
 2 1/2 lbs  cream cheese, room temp. (very soft)
 1 3/4 cup  sugar
 1 cup      unsweetened cocoa powder, sifted
 3          large eggs, room temp
 1/2 cup    whipping cream
 2 Tbs      coffee liqueur
 1 1/2 Tbs  Frangelico (hazelnut liqueur)
 1 tsp      vanilla extract
 
 Chocolate Glaze:
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 1/4 cup    coffee liqueur
 1/4 cup    Frangelico
 2 Tbs      dark rum
 12 oz      bittersweet chocolate (not unsweetened) 
            or semisweet chocolate, chopped
 1/4 cup    whipping cream
 1/4 cup    (1/2 stick) unsalted butter
 For filling: Position rack in center of oven and preheat to 300F.  Line
 bottom of 9-inch-diameter springform pan with 2 3/4-inch-high sides with
 waxed paper.  Spray paper with nonstick vegetable spray.  Using electric
 mixer, beat cream cheese and sugar in large bowl on low speed until
 smooth.  Gradually mix in cocoa.  Beat in eggs, 1 at a time.  Gradually
 add cream, coffee liqueur, Frangelico and vanilla and beat until mixture
 is smooth. 
 
 Transfer filling to prepared pan.  Bake until outer 3 inches of cake
 puff and center is gently set but moist looking, about 1 hour 30
 minutes.  Cool on rack.  Cover and refrigerate until cake is well
 chilled, at least 6 hours.  (can be prepared 1 day ahead)
 
 For Glaze: Boil coffee liqueur, Frangelico and rum in heavy medium
 saucepan until reduced to 1/4 cup, about 3 mintues.  Reduce heat to low
 and add chocolate, cream, and butter.  Stir until mixture is smooth. 
 Cool until mixture is thick but still pourable, stirring occasionally,
 about 45 minutes. 
 
 Using small sharp knife, cut around pan sides to loosen cake.  Release
 and remove pan sides.  Pour chocolate glaze over cake.  Spread smoothly
 over top and sides covering completely.  Chill until chocolate is is
 firm, at least 2 hours. 
 
 Invert cake onto serving platter.  Peel off paper.  Smooth top.  Using
 warm knife, cut into wedges and serve.