Devil's Chocolate Cheesecake

Finally the very 1st post!! This cheesecake turned out so yummy, I hope you guys love it!!
Enjoy!
Ingredients

Crust:
1 1/3 cups graham cracker crumbs
1/2 stick butter
1 tablespoon cocoa

Cheesecake filling:
6 oz. bittersweet or semisweet chocolate, chopped small
2 1/2 cups cream cheese(I used half fat cream cheese for 1 of the packages)
3/4 cups sugar
1 tablespoon custard powder (I substituted w/ vanilla pudding powder)
3 large eggs
3 large egg yolks
2/3 cups sour cream(I used fat-free to make it less fattening)
1/2 teaspoon cocoa, dissolved in 1 tablespoon hot water

Sauce:
3 oz. bittersweet chocolate, finely chopped
1/2 cup heavy cream
1 teaspoon dark corn syrup

9-inch springform pan

Preheat the oven to 350 degrees F

to make the base, process the graham crackers to make rough crumbs and then add the butter and cocoa. Process again untill it makes damp, clumping crumbs and then tip them into the pan. Press the crumbs into the bottom of the pan to make an even base and put into the freezer while you make the filling.

Put a kettle on to boil.

Melt the chocolate either in a microwave or double boiler, and set aside to cool slightly

Beat the cream cheese to soften it, then add the sugar and custard powder, beating again to combine. Beat in the whole eggs and then the yolks, and the sour cream. Finally add the cocoa dissolved in hot water and melted chocolate and mix to a smooth batter.
Take the springform pan out of the freezer and line the outside of the pan with a good layer of cling wrap, and then another layer of strong foil over that. This will protect it from the water bath.
Sit the springform pan in a roasting pan(I used a big turkery roaster) and pour in the cheescake filling. Fill the rasting pan with just boiled water to come about half way up the cake pan and bake in the oven for 45 mins. to 1 hour. The top of the cheesecake should be set but the underneath should still have a wobble to it.
Peel away the foil and cling wrap and sit the cheesecake in it's pan on a rack to cool. Put in the refrigerator once it is no lnger hot, and leave to set, covered with plastic overnight. Let it lose it's chill before unspringing the cheesecake to seve.
To make the chocolate sause: very gently melt the chopped chocolate, cream and syrup. When the chocolate has nearly melted, take off the heat and whisk it to a smooth sauce. Let it cool a little, and pour it over the chocolate cheesecake on it's serving plate.