In a food processor, blend the Oreos (with cream), brown sugar, and melted butter into fine crumbs. Press about a tablespoon each into the bottom of lined cupcake pan, or, individual silicone cupcake molds.
If baking these in the Instant Pot, place the baking cups in the freezer while making the cheesecake mixture. This helps set the crust.
Make the Cheesecake Filling
Beat the room temperature cream cheese until airy and smooth, about 30 seconds. Sift in the cocoa powder, sugar, and cornstarch. Beat until well combined, about 45 seconds. Add the egg, and vanilla, and beat until everything is completely combined.
Using an ice-cream scoop, divide the filling evenly among the cupcake molds.
Bake it in the Oven or Instant Pot
Bake in a pre-heated oven at 350F, for 17-20 minutes. Cool for 30 minutes at room temperature before refrigerating.
Instant Pot Method
Fill a cup of water in the inner pot. Place a trivet and place 4 filled cupcake molds on top. Carefully place another tall trivet, and place another 4 cupcake molds on top. Depending on your cooker size, you may have to bake the 12 cupcakes in two batches. For more baking options, refer to the notes above.
Close lid. Set valve to sealing position (if using duo). Pressure cook on Manual/Pressure cook for 7 minutes. Wait for natural pressure release after cooking.
Remove cheesecakes and cool for 5 mins. Then carefully run your finger around the cupcake mold, gently separating the cheesecake from the mold. This prevents it from cracking when it's chilling in the fridge. Cool for 30 minutes at room temperature before refrigerating.
Chocolate handles (optional)
Line a baking sheet with parchment paper. Melt your preferred chocolate chips in the microwave. Cool for 5 minutes and transfer to a piping bag or ziplock bag. Seal the bag and cut off the tip of the corner for the chocolate to flow. Now pipe the chocolate in the shape of an inverted "C" shape. Allow ½-1 inch space between each handle. Let these cool for a few hours. You can insert these chocolate handles into the cheesecake before serving.
Using fresh or canned whipped cream, top the hot cocoa cheesecakes and dust with some unsweetened cocoa!