- 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.