First, soak jaggery in warm water(till immersing level) , crush it well. Then heat it up until it is slightly thick. Strain and keep aside.Let it cool for few mins.
Meanwhile, take wheat flour in a mixing bowl , add jaggery syrup to it and mix well then add required water to make it to a pouring consistency.Then add rice flour and mix well without any lumps,then add mashed banana,coconut,cardamom powder,salt and cooking soda.
Then mix well. Finally heat paniyaram pan grease each hole with little oil - then spoon the batter and add it to each hole. Keep covered and cook for a minute. Once the top gets cooked turn over to other side and cook till golden brown.
Fluffy and soft appams ready. Serve hot !