Begin by preparing the batter. In a large mixing bowl, combine the plain flour, rice flour, and corn flour. Sprinkle in the salt and turmeric powder, then gradually pour in the water while stirring continuously. Mix until you achieve a smooth, lump-free batter with a thick, coating consistency.
Heat a generous amount of peanut oil in a deep frying pan over medium heat. Once the oil is hot enough (you can test with a drop of batter—it should sizzle immediately), begin dipping the cempedak pieces into the batter, ensuring they are fully coated.
Carefully place each coated cempedak piece into the hot oil. Avoid overcrowding the pan to ensure even frying. Fry the pieces until they are golden brown and crispy on the outside, turning occasionally to brown them evenly.
Once cooked, transfer the fried cempedak onto a plate lined with paper towels to drain excess oil.
Drizzle the warm, melted gula melaka over the crispy fritters just before serving. Serve hot for the best texture and flavor.