1. Line the base of the tins with butter paper or grease the bases and dust either with maida or sugar until well coated.
2. In a mixing bowl, sift the flour and baking powder.
3. Add salt, sugar, butter, water and vanilla, and beat the mixture using a wooden spoon or a beater till well blended.
4. Add the dahi to the batter and beat until smooth. The batter looks almost glossy when done. Transfer the batter into the two tins.
5. Heat the pressure cooker (empty), covered with the lid but without the pressure, for 3-4 minutes on high heat, then place one cake tin in it.
6. Close the lid without the pressure, lower the flame and let it cook until done (about 30 minutes).
7. Repeat with the other tin. Serve.
Key Ingredients: all purpose flour, vanilla essence, salt, sugar, yogurt, butter, baking powder