Line the base of the tins with butter paper or grease the bases and dust either with maida or sugar till well coated.
Sift the flour and baking powder and transfer into a mixing bowl.
Add the salt, sugar, butter, water and vanilla.
Beat the mixture using a wooden spoon or a beater till well blended.
Add the dahi to the cake batter and beat till smooth. The batter looks almost glossy when done. Transfer the batter into the two tins.
Heat the pressure cooker (empty), covered but without the pressure for 3-4 minutes on high heat, then place one cake tin in it.
Cover again without the pressure, lower the flame and let cook till done (about 1/2 an hour).
Repeat with the other tin. Serve.
Key Ingredients: all purpose flour, vanilla essence, salt, sugar, yogurt, butter, baking powder