Put the cold water, peanut oil, flavouring and icing sugar together, stir until icing sugar dissolved.

Sift the gao fen into a bowl, gradually add the above syrup and use hand to knead until it forms a soft and evenly mixed dough. Transfer the dough to a plastic bag of about 20 cm wide.

Use a rolling pin to roll it flat following the size of the plastic bag with about 0.5 cm thickness. Make it into a square shape. Use a scissor to cut open the plastic bag.

Brush the cake with your preferring colouring and roll it like rolling a sushi. Ensure that the rolling is tight.

Transfer to a work surface lightly dusted with gao fen and use a sharp knife to cut into small pieces of your desired thickness. The cake can be eaten immediately when it is prepared. Store in an air tight container in fridge or at room temperature.