Step 1

Preheat oven to 350°F (180°C), with rack in middle of oven.

Step 2

Pulse the cookies in a food processor or blender until finely ground. Put in a large bowl, and stir in the melted butter. 35 oreo cookies 5 Tablespoons (71 g) unsalted butter

Step 3

Press the crumb mixture firmly into the bottom and slightly up the sides of a 9 inch springform pan, using the bottom of a measuring cup (or you can use your fingers).

Step 4

Place the pan on a baking sheet and bake at 350°F (180°C) for 10 minutes. Remove from the oven and let cool.

Step 5

In the bowl of a stand mixer, fitted with a paddle attachment, beat cream cheese on low speed until lightly beaten and creamy then add the sugar and cornstarch and beat on medium speed for 4 minutes. 32 ounces (four 8-ounce blocks) cream cheese 1 ½ cups (300 g) granulated white sugar 1 tablespoon cornstarch

Step 6

Add the salt and vanilla extract, beating after each addition. Add the eggs, one at a time, beating for one minute after each addition. Add the sour cream and Irish cream, beat until incorporated. Scrape down the sides of the bowl and along the bottom to make sure all of the cream cheese has been incorporated. pinch salt 2 teaspoons vanilla extract 4 large eggs ⅔ cup (160 g) sour cream ⅔ cup (160 ml) Baileys Irish cream

Step 7

Lower the heat on the oven to 325°F (160°C).

Step 8

Wrap the outside of the springform pan in three layers of aluminum foil, ensuring none of the pan is exposed. You can also use a slow cooker liner.

Step 9

Prepare pan and boiling water: Place the foil-wrapped springform pan in a large, high-sided roasting pan. Prepare 2 quarts of boiling water.

Step 10

Pour the cheesecake filling into the springform pan, over the graham cracker crust. Smooth the top with a rubber spatula.

Step 11

Place the roasting pan with the springform pan in it, in the oven.

Step 12

Carefully pour the hot water into the roasting pan, pouring until the water reaches halfway up the side of the springform pan.

Step 13

Bake at 325°F (160°C) for 80-90 minutes until the edges of the cheesecake are set and slightly golden brown, and the middle of the cheesecake is set but still slightly wobbly. If the top is browning too much lightly tent the top with foil.

Step 14

Turn off the heat of the oven. Crack open the oven door and let the cake cool in the oven, as the oven cools, for another hour, which will help prevent the cheesecake from cracking.

Step 15

Cover the top of the cheesecake with a paper towel (to help with condensation forming) and then cover in foil. Chill in the refrigerator overnight.

Step 16

Chop chocolate into fine pieces and place into a heatproof bowl. 4 ounces semi-sweet or bittersweet chocolate

Step 17

Heat cream and Baileys Irish cream in a saucepan over medium heat until simmering, but not boiling. Pour hot cream over the chopped chocolate. Let sit for 5 minutes, do not stir. ½ cup (120 ml) heavy cream 2 Tablespoons Baileys irish cream

Step 18

After 5 minutes, whisk until smooth.

Step 19

Pour over the cooled cheesecake before serving. Smooth with spatula if necessary. Transfer to the refrigerator until set, about 15 minutes before slicing and serving.