In a bowl, pour water, sugar, salt and stir to dissolve.
Pour in the vegetable oil and add the all purpose flour. Mix thoroughly.
Gradually add water until doughy. Add more if your mixture turned out too dry. If its too wet, add more flour.
Knead the dough for few minutes or until the texture turn smooth.
Divide it into 2 pieces. Flatten the first cut using a rolling pin. Check if its enough for the pan you use.
Grease the baking pan with oil and transfer the flattened dough. Trim the edges and poke some holes using a fork.
Put in the coconut filling and set aside.
For the remaining dough, flatten and put on top of the pan. Trim edges.
Pinch to seal and design edges. Poke some holes on top using fork. These holes will prevent it from forming bubbles.
Brush top with egg. Preheat oven and bake at 170 ° C for 40 minutes.