In a bowl, add the egg, sugar, and a pinch of salt. Whisk well until the sugar dissolves and the mixture becomes slightly frothy.
Add the rice flour and black sesame seeds. Mix well.
Pour in the coconut milk and water, then whisk everything together to form a smooth, lump-free batter.
The batter should be slightly thin and flowing. If it feels too thick, add 1 tablespoon water at a time until the right consistency is reached.
Heat enough oil in a kadhai on medium heat for deep frying and place the achappam mould inside the hot oil.
Carefully remove the mould from the oil and dip it into the batter, making sure the batter coats the mould only up to ¾ of its height (do not cover the top edge).
Immediately place the mould back into the hot oil. The batter will begin to cook and the achappam will release from the mould after a few seconds.
If it doesn’t release easily, gently shake the mould or use a skewer to help it slide off.
Fry until golden brown and crisp, flipping if needed for even cooking.
Remove from the oil and place on paper towels to drain excess oil.
Repeat the process, reheating the mould in the oil before dipping it back into the batter.
Allow the achappam to cool completely; it will become extra crisp as it cools.
Recipe by Bake with Shivesh at https://bakewithshivesh.com/achappam/