First heat a small pan. Optionally add ½ tsp ghee / oil. Roast the chopped coconut pieces until it turns slightly golden brown. Transfer to a plate and let it come to room temperature.
To the same pan, add the jaggery along with ½ Cup of water. Heat in medium flame until the jaggery is completely melted. Filter the jaggery syrup through a fine metal mesh strainer and let it come to room temperature.
Then, roughly chop / mash the bananas and add it to the mixie. Grind it to a smooth paste.
Now, take a heavy bottomed pan and dry roast the rice flour and whole wheat flour for about 1 min until a nice aroma arises. Do not roast until the color changes. Let it come to room temperature.
Now, take a large mixing bowl, add the rice flour, wheat flour, jaggery syrup, banana paste, coconut and mix well into a batter. The batter should be in the consistency of a idly batter, add water accordingly. I used about 1 Cup of water. Leave the batter to rest for 20 mins.
After 20 mins of resting, add the salt, baking soda, cardamom powder, roasted sesame seeds and mix well until combined.
Now heat the paniyaram pan with some oil / ghee in each hole and fill ¾th of the hole with prepared batter. I used 1 Tbsp batter per hole. Cook in low-medium flame until small holes appears on top and the side turns golden brown. Now flip the appam using the spatula or spoon and cook the other side until they are fully done. Check by inserting a toothpick in the center and it should come out clean, with no raw batter sticking to it.
Transfer to the serving plate and enjoy hot.