Preheat the oven to 350°F. Separate the Oreo cream filling from the cookie layers and set aside for later. Crush the Oreo cookie layers so you are left with cookie crumbs.
Beat the eggs and sugar until frothy and add the Oreo cookie crumbs. In a separate bowl, combine the flour, cocoa powder, baking powder, baking soda, and salt, and add the dry ingredients to the wet ingredients. Then stir in the vegetable oil, milk, and hot water.
Pour the cake batter into a baking sheet lined with parchment paper, bake for about 30 minutes or until done, and then let it cool completely.
Take the cream filling from the Oreo cookies that you set aside earlier, combine it with the whipped cream, cream cheese, and powdered sugar, and mix well. Spoon the cream into a piping bag and refrigerate for about 30 minutes.
Use an Oreo tin or an equally large canister to cut out 2 even circles from the chocolate cake.
Pour the tempered chocolate into the lid of the Oreo tin. Let the chocolate cool briefly, place one of the cake circles in the lid, and let the chocolate set.
Pipe the cream filling from the piping bag on the other cake circle. Place the cake circle with the chocolate lid on top of the cream filling and remove the tin lid.