Marble cake-Pressure cooker method

When I was small, my mother used to bake so many cakes using pressure cooker method as she did not have an electric oven at that time. As this method has be tried and tested so many times in my house, I can assure you that your cake will turn out well..Dont worry to those who do not have an oven..u can also bake a cake without an oven..which gives same texture like a baked cake....

Ingredients:-

All purposeflour-1c
Sugar-3/4c
Butter/Oil-1c(100g) i usd oil here -1cup
egg-2
Coco powder-2 tbspn
baking powder-1tespn
baking sda-1/2 tespn
vanila essence-1tespn

Method:- 

1 Sift flour+baking powder+baking soda (3 times) and keep it aside
2 Beat together sugar and butter(Oil) ,
3 Add in the egg yolk one at a time and continue beating
4 Then add the egg whites also
5Add vanilla essence
6 Finally slowly fold in the flour mixture
7 Divide the dough in to 2 eql parts
8 and add coc powder in to 1 portiona n mix all these well
9 The most important part is assembling the cake batter in a baking pan. Pour 3 heaped tablespoons  
    of plain batter into the middle of the baking pan. Then pour 3 tablespoons of cocoa batter in the
    center on top of the plain batter. Continue alternating with plain and cocoa batter without pausing
    for the batter to spread.
10  Then place cooker in med flame abt 10 mins(Dats preheating)
11 then place alumium plate dat v gt along with cooker..n place our cake tin(if u dnt hav one.dnt
     wory place an aluminium or steel plate )

12 Close the lid n cook in low flame for abt 50-55 mins
or till a screwer when pricked comes out clean......

Note:-

no need to remove the rubber gasket
dont put cooker's weight also
no need 2 add water