Add lye water into lotus seeds, mix well and leave aside for 20 minutes. Pour in boiling water and coverup for 20-30 minutes. Strain and wash the lotus seeds to remove the skin.
Boil lotus seeds till soft. Put them into a blender with some water and blend into a thick paste.
Heat wok with a quarter portion of oil and a quarter portion of sugar. When sugar turns light brown, put in blended lotus paste and the remaining sugar. Stir constantly until paste is smooth and thick in consistency. Add in the rest of the oil gradually. Keep stirring the paste until thick. Lastly, stir in maltose and stir well to blend.
Sieve in 1 tbsp kao fun for a thicker and firmer consistency in the paste. Leave overnight before use.