To Prepare Custard Filling
- In a small saucepan, add milk and half of the sugar. Heat and stir over medium-low heat and cook until it reaches about 49°C or no more than 65°C. Do not overheat. Leave in saucepan while you complete the next steps.
- In a large bowl, mix corn starch, all-purpose flour and the remaining sugar.
- Add egg yolks to a separate small bowl, stir to break up the egg yolks, then pour it into the dry ingredients. Mix until well combined.
- Next, add warm milk to the egg mixture ¼ cup at a time. Whisk continuously until milk is fully incorporated and the mixture is thin and smooth. Repeat until all the warm milk is mixed.
- Pour the mixture back into the saucepan and cook under medium heat until the mixture thickens (about 5 mins). Tip: Keep a close eye on the mixture as it will thicken suddenly.
- Remove from stove and give it a few stirs. Then add in butter and vanilla extract and mix well.
- Strain the custard through a strainer into a dish lined with cling wrap. Press with a spatula to remove any lumps. Cover custard surface with another layer of cling wrap to prevent skin from forming. Chill custard for 1 hr.
- After chilled, take custard and scoop about 1 tbsp and roll into a small ball onto a lined tray. Cover and chill or freeze for 30 mins or until it is easy to handle.
To Prepare Mochi Dough
- Prepare a large steamer pot with a steaming basket or trivet and turn on stove to begin heating.
- In a small bowl, mix milk, oil and vanilla extract together.
- In a medium bowl, add glutinous rice flour, rice flour and cornstarch and mix well. Then sift in icing sugar to break up any lumps. Pour in the milk mixture gradually and mix until well combined and a watery batter is formed.
- Strain the batter into a large bowl to remove any lumps. Steam the mixture in the prepared steamer (water should be bubbling) for 20 mins. At 15 mins, check to see how the dough is cooking by poking through the middle with a fork. If any dough is uncooked, break through the dough and steam for a further 5 to 8 mins. The dough is ready when it is stiff. Once cooked, remove from steamer and let it cool for about 10 mins.
- Once the dough has cooled down, tip it over onto a clean surface (do not oil or flour the surface). Knead the dough for 5 to 8 mins until soft and smooth.
- Use a kitchen scale to divide 3 or 4 equal portions. Tint each portion with your chosen food colouring by kneading together. Keep dough wrapped up or covered while you work. Roll each portion into logs and divide the logs into 5 or 6 portions. Roll each of these portions into balls, then cover so they do not dry up.
Assembling the Mochi Mooncakes
- Prepare a 50g mooncake punch mould.
- Flatten a mochi ball with a rolling pin, pinch the edges to make them thinner. Place a chilled custard ball in the middle and close the outer layer edges until the custard ball is completely concealed. Roll with both palms until you get a round ball.
- Dust some corn starch on and insert into mooncake punch and press until compact before releasing.