• Preheat the oven to 325F degrees.
• Wrap the outside of a 9-inch springform pan with a disposable oven bag (you may need to trim the bag). Twist the edge so that the wrapping is tight and tie with the key lock tie. Then wrap the outside of the pan in aluminum foil at least 3-4 times. Alternate the direction of the way you wrap to ensure that the sides and all seams are covered.

Cookie Crust

• Add the cookies (wafers and filling) to a food processor and pulse until fine crumbs. Or place in a freezer bag and crush with a rolling pin.
• Mix the crumbs with the melted butter.
• Press the mixture into the bottom of the springform pan, creating a slight lip around the edge.
• Bake in the preheated oven for 10 minutes. Then remove from the oven (keeping the pan wrapped in foil) and keep the oven turned on.

Cheesecake Filling

• Chop the chocolate into very small pieces and place in a large heatproof bowl. Microwave on medium power (not standard or high power) for 45 second intervals, removing the bowl from the microwave and giving it a stir in between each, until smooth. Or melt in a double boiler ensuring that the water in the saucepan underneath is gently simmering and not touching the bottom of the bowl containing the chocolate.
• In a very large bowl, beat the cream cheese, sugar and cornstarch until smooth and creamy - about 3-5 minutes. Continually turn off the mixer and scrape down the bottom and sides of the bowl.
• In a small bowl, whisk together the 4 large eggs and additional 2 egg yolks. Whisk the eggs into the cheesecake batter about 1/2 at a time. I do this by hand to avoid overmixing. If using an electric mixer, do a few stirs by hand first then mix on a low speed. Stop mixing as soon as you no longer see pieces of egg.
• Pour the batter over the prepared crust (the springform pan should still be wrapped).

Baking, Cooling & Chilling the Cheesecake

• Place the springform pan wrapped in aluminum foil in the middle of a large roasting pan.
• Pour about 1/2 - 1 inch (1-2 cm) of boiling water into the roasting pan.
• Place the roasting pan (with cheesecake inside) in the oven and bake for 55-70 minutes, or until the top looks just set and if you give the pan a gentle nudge the cheesecake has a slight wobble - similar to a bowl of pudding or jelly.
• Turn off the oven, open the oven door and cool the cheesecake in the oven with the door open for about 30 minutes. Then remove the roasting pan from the oven and cool the cheesecake (in the roasting pan) until it reaches room temperature.
• Once room temperature, remove the springform pan from the roasting pan, cover with aluminum foil, and place in the fridge to chill for at least 6 hours or overnight.

Chocolate Ganache

• Chop the chocolate into very small pieces and place in a heatproof bowl.
• Heat the cream until almost boiling and pour over the chopped chocolate. Let it sit for about 2-5 minutes, then whisk until smooth.
• Remove the cheesecake from the fridge, gently trace around the edge of the pan with a thin, sharp knife. Unclamp the outer ring of the springform pan. If there's any condensation on top of the cheesecake, blot it with a paper towel.
• Pour the chocolate ganache over the cheesecake, letting it drip over the edges. Optionally, sprinkle a few chocolate shavings on top and/or decorate with raspberries.
• Place the cheesecake back in the fridge for 30 minutes for the ganache to firm up.
• To serve cut the cheesecake into slices using a sharp, thin, non-serrated knife (do not use a table knife). Be sure to slice all the way through the Oreo crust.