Crust
1 1/2 cups chocolate cookie crumbs
1/4 cup melted butter
Filling
24 ounces softened cream cheese
1 cup sugar
2 tablespoons cornstarch
3 eggs
1/4 cup sour cream
2 teaspoons vanilla extract
1 cup melted, cooled milk chocolate chips
1 cup canned solid pack pumpkin
1 teaspoon pumpkin pie spice
1 cup melted, cooled semi-sweet chocolate chips
Glaze
1/2 cup semi-sweet chocolate chips
2 tablespoons butter
1 tablespoon light corn syrup
Crust
Heat oven to 350°F. Spray 8 inch springform pan with nonstick cooking spray. Mix crumbs with butter till evenly moistened. Press firmly over bottom of pan. Bake 8-10 minutes till set. Cool. Wrap outside of pan with foil. Reduce temperature to 300°F.
Filling
Beat together cream cheese, sugar and cornstarch till mostly smooth. Beat in eggs, one at a time, just till blended. Stir in sour cream and vanilla. Divide batter evenly between 3 bowls. Stir melted milk chocolate into one bowl and pour over crust in an even layer. Whisk pumpkin and spice into second bowl and carefully spread over chocolate layer. Stir semi-sweet chocolate into remaining bowl and carefully spread over pumpkin layer. Set pan in center of large roasting pan. Place on oven rack and add boiling water to halfway up sides of pan. Bake 1 1/2-1 3/4 hours till set but center still jiggles. Turn off oven and let cake cool in oven with door shut. Cool further on rack. Cover and chill 4 hours or overnight.
Glaze
Run knife around pan sides to loosen cake and remove pan sides. Place cake on serving plate. Stir glaze ingredients together over low heat till chocolate melts and mixture is smooth. Remove from heat and cool slightly. Spread cooled glaze over top of cake to the edge, some may drip down sides. Chill till glaze sets.