Soak blackgram dal and rice for 2 hours. Grind and make a smooth paste. Add salt to it. Take out water form cheese. Add grated coconut, sugar and cardamom paste to make the stuff and fry for 5-10 minutes. Heat oil in a tawa. Pour batter to make a thick round shape. Turn upside down. Spread some stuff over it. Pour some batter over it and spread it to cover the stuffing. Pour oil over it and again turn the upside down. Repeat the same process for 3-4 times to make a thick pitha. Take out and cut into pieces & serve.