Wash Pandan leaves, remove ends that are withered or gone bad. Cut into 5cm lengths. Put some in a blender, add a little water and blend (combination of pulse and normal blend), gradually add all the Pandan leaves, adding more water to help with blending. Strain the fibrous solid out, squeeze to collect all Pandan juice.
Mix coconut powder, sugar and salt well. Use some of the 600 ml water to mix and dissolve the coconut powder dry mix into a thick liquid, then mix in the balance of the water.
Pour liquid into a medium microwave proof bowl or deep dish. Drain the glutinous rice. Add and mix soaked rice to coconut mixture.
Place in microwave and cook for 10min.
After 10min, stir and mix partially cooked rice evenly. Return to microwave and cook for another 10min. Again remove the more or less cooked rice, stir and mix evenly, this time drip in the cooking oil as the rice in stirred and mixed. Cover the bowl or dish with Gladwrap, and microwave for another 5 min. Remove, fluff the cooked rice to cool.
Mix rice flour, tapioca flour and sugar in a mixing bowl.
Line a 10" square tray with Glad wrap. With a disposable glove, place cooked rice in tray and pat down to pack down and level rice in tray.
Mix coconut powder into some Pandan juice. Microwave for 30sec to warm the mixture.
Add the balance of Pandan juice to the dry flour mixture and mix well. Transfer both Pandan mixture to a pot and heat on medium heat, stirring continuously to thicken the Pandan/flour mixture until slightly thick.
Add boiling water to a wok with lid to have steamer ready.
Pour the thickened Pandan mixture over the rice layer in the cake tray. Place tray in the steamer and steam under high heat for 35 to 40min.
When cooked firm, remove from steamer. Use paper towel to dab off any water on top of the kuih. Cool slightly. Hold the glad wrap around the finishe kuih and remove from tray.
Leave to cool further to room temperature and serve.