Firstly, in a pressure cooker, add 1½ cup of salt and place a cooker rack or any cup.
Close the lid of cooker without keeping the gasket and whistle.
Heat for 5 to 10 minutes. as a result, gives a preheat oven atmosphere.
Meanwhile beat 1 cup milkmaid, ¼ cup oil, ¼ cup milk, 1 tsp vanilla extract and 1 tsp vinegar in a large mixing bowl.
Now in a sieve take 1 cup maida, 2 tbsp cocoa powder, ¼ tsp baking soda, ½ tsp baking powder and a pinch of salt. sieve everything well.
Combine well with cut and fold method adding warm milk if required.
Do not to over mix the cake batter as it turns chewy. Further, transfer the cake batter into the cake mould (width: 15 cm, height: 6 cm, length: 17 cm).
Then carefully place the cake tray into the cooker.
Close the lid of cooker without gasket and whistle. Cook for 40 minutes.
Finally, serve the cake or store in airtight container.