Sieve all the dry ingredients (all purpose flour, baking powder, baking soda and salt) very well.
Beat the egg by adding sugar little by little for 6-7 minutes. Then add oil and milk, Mix slowly.
After that add the remaining dry ingredients little by little and mix slowly.
Pour it into a greased 7 inch cake tin. Place on a bed of salt in the cooker and lock the lid without the whistle. Cook it on a a low flame for 40-45 minutes. (Use a 5-litre pressure cooker for this recipe. Put 1 cup of salt at the base of the cooker, Remove the whistle from the cooker's locking cap—Preheat the cooker on low flame.)
Add Oreo crumbs and mix.
Remove cakes from pan and allow to cool for about 10 minutes, then remove to cooling racks to cool completely. Make icing while cakes cool. Cut the cake into 3 or 4 layers.
Beat whip cream until stiff and add Oreo crumbs into it. Mix well.
Place 1 cooled layer on a large plate. Sprinkle some sugar syrup and cover the top with a 1-inch thick layer of Oreo Cream Filling. Top with the 2nd cake layer and continue the process till the last layer of cake. Cover the top with a thick layer of cream and garnish the tall layer cake with chocolate syrup and Oreo cookies.
Oreo cake is ready now. Slice and serve cake. Leftover cake can be covered and stored in the refrigerator for up to 3 days.