Lightly grease a 20cm (base size) round cake pan with oil. Wipe the pan with paper towel to ensure it is well coated and to remove any excess oil. Place the pan in a large steamer set over a pan of water simmering over medium heat.

Combine rice flour, tapioca flour, sugar, coconut milk and water in a large bowl. Stir until well combined. Strain mixture through a sieve into a large bowl to remove any lumps, if necessary. Pour 650ml of the mixture into a bowl and set aside. Add pink food colouring to the remaining bowl to tint pink, then stir to combine well.

Reduce heat to medium-low. Pour 160ml (⅔ cup) of the pink coconut mixture into the prepared cake pan. Cover and steam for 7 minutes or until just set (the layer may look a little bubbly on the surface but this will smooth out as you keep layering). Stir the white coconut mixture until smooth (the flours settle over time, so it's important to stir the mixture before measuring and pouring into the pan). Carefully pour 160ml (⅔ cup) of the white coconut mixture over the pink layer. Cover and steam for 7 minutes or until this layer is just set. Repeat, alternating with remaining pink coconut and white coconut mixtures (making sure to stir each mixture before pouring into the pan) and refilling the water level as necessary, to make 9 layers in total, finishing with a pink layer.

Remove the pan from the steamer and set aside for 3 hours to cool completely. Cut into diamond or rectangle pieces, to serve.