Cook the blue flowers to get a nice blue colour and let it cool down.
Wash the glutinous rice and divide it into two bowls. Pour water into one bowl and pour butterfly pea flowers water into the other bowl. Soak overnight or at least 4 hours.
Dry the soaked glutinous rice and place it in a large plate. Put pandan leaves and pour in the thick coconut milk mixed with salt.
Put glutinous rice in a steamer and steam for 30 minutes, then simmer for 5 minutes. After that, take out the glutinous rice and stir well.
Put the glutinous rice into the mould with banana leaves. Press it with a heavy object for at least 2 hours to make the glutinous rice cake firm. Slice it up and eat it.