Purple Sweet Potato Hee Pan or Ki Ka Ku (ovenight sponge dough) 紫薯喜粄 (隔夜发酵法)

So long did not make some Hee Pan (steamed glutinous rice buns). After i tried purple sweet potato version from a kuih-muih store after hiking, it tasted so soft but not sure what special ingredients they have added to make them so soft. So better i make it by myself as i know what ingredients that i used.

This time i tried with overnight sponge dough. Same like making bread with overnight sponge dough, it always keep the buns stay moist and soft.

Still use back my mother's recipe which the dough is easy to handle and not sticky at all.

to check the bun is done with proofing, just pressing the bun with a finger, if the dough doesn't bounce back then it is ready to be steamed.

Purple Sweet Potato Hee Pan or Ki Ka Ku紫薯喜粄

For sponge dough

1tsp instant yeast

150g plain flour

150g water

For the dough

250g glutinous rice flour

70g plain flour

150g caster sugar

100g vegetable oil (corn oil, sunflower oil etc)

1/2tsp instant yeast

100g mashed purple sweet potato

70g water or adjust accordingly

Banana leaves

Method

1. Mix all ingredients for sponge dough and mix it well. Cover with cling film and keep in room temperature for overnight ( I kept for 12hrs).
2. Mix all ingredients for the dough and overnight sponge dough in a mixer, slowly add in water to knead till smooth and not sticky dough, adjust water accordingly.
3. Grease the banana leaves with cooking oil. Divide dough into 60g each.
4. Shape into smooth round ball, flatten the dough by pressing your palm on the ball. Then place on top of a greased banana leaf. Keep aside to proof for 1.5-2hrs or until you pressing with a finger in and if the dough doesn't "bounce" back, then it is ready.
5. Arrange on steaming tray, steam on medium heat for 20mins. To avoid water dripping on the buns, wrap the steamer cover with cloth.
6. Keep unfinished Hee Pan in a food container in room temperature. It stay soft even till the next day.

Sponge dough reference from aunty yochana, recipe by Sonia a.k.a Nasi Lemak Lover