Instructions

• Pulse the 20 Oreo cookies (with filling) in a food processor until fine crumbs form. Press the crumbs into the bottom and about 1 inch up the sides of a 6" or 7" springform pan using a measuring cup or the bottom of a glass. Place the prepared crust in the freezer while you make the filling.
• In a large bowl, beat the 16 ounces cream cheese (room temperature) on high until smooth and light.
• Add 1/4 cup white sugar and 1 tablespoon cornstarch to the cream cheese and mix just until combined.
• Beat in 1/2 cup sour cream until just incorporated, taking care not to overmix.
• Add the slightly cooled, melted 8 ounces semi-sweet chocolate, 1/4 cup unsweetened cocoa powder, 1/2 teaspoon espresso powder, and 1 teaspoon vanilla. Mix until the mixture is uniform.
• Add the 2 eggs one at a time, mixing on low and stopping as soon as each egg is incorporated. Do not overmix.
• Pour the filling into the prepared Oreo crust. Tightly cover the top of the springform pan with aluminum foil to prevent condensation from dripping onto the cheesecake.
• Pour 1 cup of water into the Instant Pot inner pot and place the trivet inside. Fold a long strip of aluminum foil several times to make a sturdy sling, slide the sling under the springform pan, then set the pan on the trivet with the sling ends accessible so you can lift the pan out later.
• Close the Instant Pot lid and set the valve to Sealing. Cook on High pressure for 35 minutes. When the cook time ends, allow a natural pressure release until the pressure has fully released, then open the lid.
• Carefully lift the pan from the Instant Pot using the foil sling. Remove the foil covering the pan and place the pan on a wire rack to cool to room temperature.
• Once cooled completely, transfer the cheesecake (still in the pan) to the refrigerator and chill overnight (at least 8 hours) to fully set.
• To make the ganache, combine 1/2 cup chocolate chips and 1/2 cup heavy whipping cream in a microwave-safe bowl. Microwave in 30‑second intervals, stirring between each interval, until the chocolate is fully melted and the mixture is smooth. Let the ganache cool a few minutes until slightly thickened but still pourable.
• Pour the ganache over the chilled cheesecake and spread to the edges. Return the cheesecake to the refrigerator until the ganache is set (about 30 minutes to 1 hour).
• Remove the springform ring, slice, and serve. If desired, wipe a knife clean between slices for neat edges.