Lightly grease an 8 inch spring form pan. Cover the outside of the pan with aluminum foil. Combine cookie crumbs and butter. Press into bottom of pan and up the sides about 1 inch.
In a large bowl, mix cream cheese and condensed milk, with a mixer on medium speed, until fluffy. On low speed, add eggs one at a time. Insert melted chocolate and vanilla. Mix until well blended. Pour into crust. Cover tightly with aluminum foil.
Place a metal rack in the removable cooking pot of the pressure cooker. Pour in water. Fold a 24 inch length of foil in half lengthwise, making it narrow. Center the pan on the foil and lower into the pressure cooker. (The foil is used as a swing to lower the pan.) Fold the ends of the foil down on top of the foil covered pan. Cover, set to high pressure, and set time for 20 minutes.
Let it sit for an undisturbed 10 minutes after cooking time has elapsed. Release any leftover pressure using the quick-release method. Unlock and remove the lid. Remove cheesecake from the pressure cooker by pulling up the ends of the foil swing. Remove and discard foil. Let cool to room temperature before refrigerating overnight.
Recipe courtesy of Deni, Reprinted with permission.