Insert the steam rack into the Instant Pot®. Add 1½ cups (350 ml) water.

To make the crust, coat a 7-inch (18 cm) springform pan with cooking spray. Use a food processor or a resealable plastic bag and a rolling pin to grind the cookies. Mix in the sugar, cinnamon, and butter.

Using a flat-bottomed glass, press the crumbs evenly on the bottom and 1 inch (2.5 cm) up the sides of the pan. Freeze the crust while you make the filling.

To make the filling, in a medium microwave-safe bowl melt the chocolate chips on high, stirring every 30 seconds, until melted and smooth, about 60 seconds total. Let cool to room temperature, keeping the chocolate warm enough to be pourable.

In a large bowl, use an electric mixer on medium speed to beat the cream cheese until smooth and creamy. Beat in the sugar until smooth. Add the eggs, one at a time, beating well after each addition and scraping down the sides of the bowl as needed. Beat in the sour cream and vanilla.

With the mixer on low speed, pour in the chocolate and mix in completely. Pour the filling into the prepared crust.

Tightly wrap the entire pan in aluminum foil. Using another piece of foil, make a “sling” measuring about 3 x 20 inches (7.5 x 51 cm). Use it to lower the pan into the pot.

Lock the lid. Press [Manual] and cook on high pressure for 57 minutes. Use the “Quick Release” method to vent the steam, then open the lid.

Lift the pan out and remove the foil (the cheesecake will be slightly wobbly in the center). Let cool on a wire cooling rack for 25 minutes, then run a knife around the edges to loosen it from the pan. Refrigerate for at least 6 hours or overnight, until completely set.

To make the whipped cream, in a medium bowl, whisk together the cream and confectioners’ sugar until soft peaks form.

To serve the cheesecake, remove the ring. Spread the whipped cream over the top of the cheesecake, leaving a 1-inch (2.5 cm) border. Use a vegetable peeler to shave the hunk of chocolate over the top.