Mix glutinous rice flour and corn flour together and slowly add in the water. Mix gently. Strain through a muslin cloth into a saucepan and turn the heat to medium. Stir in the sugar and cook until the mixture is thick and clear. Remove from heat and pour into the prepared tray. Set aside and allow to cool completely. Cut into 12 pieces.
To prepare glutinous rice mixture:
Soak both kinds of glutinous rice in water for 3 to 6 hours.
Place the rice in a steamer tray lined with muslin, and steam over medium heat for 30 minutes.
Mix coconut milk, sugar and salt well. Place in a pan and bring to the boil, then remove from heat. Strain the mixture through a muslin cloth.
Mix the rice with the coconut milk mixture. Stir thoroughly and set aside, covered, for 20 minutes.
To make daifuku:
Dust your hands with corn flour and flatten a piece of mochi dough to a rough circle, about 8cm in diameter. Place some glutinous rice mixture and durian in the middle and fold over to seal. Repeat until you have used up all the ingredients.