You actually dont need an oven for this.
Check out the recipe below.
(If you have a blender, you’re able to use that to hasten the process.)

Image credits: Nino’s Home via Youtube
After crushing the Oreo cookies, place them in a bowl, then add 1 tsp of baking powder.
Mix the mixture thoroughly until the cream completely dissolves.
Pour the Oreo mixture into the pan.

Next, place the pan with the Oreo mixture on top of the other pan.
Put a lid to cover.
Set it on low heat for about 40 45 minutes.

Check the cake if its ready or not by sticking a stick into it.
If the cake doesnt stick to the stick, then its cooked already.
Transfer it to a plate and let it cool off.
Mix it until it dissolves, then pour it on top of the cake when its cool already.
Decorate it with grated chocolate or anything you want.