Vattayappm is a soft and spongy rice cake. It is made with a fermented rice batter. Coconut , sugar and cardamom are the other ingredients that give it its classic taste and aroma.
Take ½ C water in a pan and bring to boil. Add the broken rice or semolina to it cook for 1 minute stirring often. The water is absorbed into the solids and a thick mix is formed. Turn off the heat and let it cool until warm to touch.
Warm the remaining water to about 100 °F or just warm to touch. Take 1/4 C water in a bowl and stir in 1 tbsp of sugar. Sprinkle the yeast on top and set aside to bloom for 5 to 10 minutes.
In a blender grind the grated coconut and 2 Tbsp sugar to a fairly smooth paste. If needed add a little water to facilitate grinding.
Mix the rice flour, the cooled starch, salt, activated yeast solution and the ground paste in a large bowl. Add enough of the remaining water to this mix to make a very thick batter. Cover the bowl and set aside to ferment in a warm place for 6 to 8 hours.
The batter has fermented enough when it almost doubled in size, and you notice yeast activity on top. Crush the cardamom seeds to a fine powder. Sprinkle the cardamom powder and the remaining sugar on top of the batter. Mix well.
Grease the bottom and sides of a steamer pan - similar to an 8- or 9-inch circular cake tin. Pour the mix into a steamer pan and set aside for 15 to 20 minutes.
Meanwhile, bring water to boil in the steamer. When the water boils set the prepared pan in the steamer. The bottom of the pan should not touch the water. Cover and steam for 20 minutes over medium heat.
The vattayappam is ready when it begins to slightly pull away from the sides of the pan. Remove from the steamer, cool to room temperature slice and serve.
The traditional way
Traditionally this cake was made with freshly ground batter. For this rice has to be soaked in water for 3 to 4 hours. Drain and grind to fine paste with just enough water.
1 to 2 tablespoons of this paste is cooked to make the cooked starch portion of the batter.
From here on the rice paste and cooked starch can be used as int eh recipe. The only difference is that less amount of water is needed to make the batter.