Preheat the oven to 325 degrees F (165 degrees C).

Pulse the chocolate wafers in a blender until finely ground. Spray the bottom of a cheesecake pan with cooking spray. Pour crumbs into the bottom of the pan and pour melted butter on top. Mix and lightly press crust over the bottom of the pan and slightly up the edges.

Bake crust in the preheated oven until lightly browned, about 8 minutes. Remove from oven and cool completely.

Combine cream cheese, eggs, sugar, yogurt, cornstarch, and cocoa powder in a bowl; beat with an electric blender until creamy. Fold in mini chocolate chips.

Pour some of the cheesecake filling into the cooled crust. Top with a handful of sliced morello cherries. Repeat layers until all cherries and filling have been added.

Pour 1/2 cup of water into a multi-functional pressure cooker (such as Instant Pot®). Add an elevated rack and set cheesecake pan on top of the rack. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 31 minutes. Allow 10 to 15 minutes for pressure to build.

Release pressure using the natural-release method according to manufacturer's instructions, about 12 minutes. Unlock and remove the lid. Remove cheesecake and let cool. Cover and refrigerate before serving, 8 hours to overnight.