Blueberry Cinnamon Rolls [Sponge Dough Method]

Very soft, moist buns that are not too oily or sweet.  A cinnamon roll recipe worth keeping and repeating.

Ingredients

[makes 16 pieces in a square baking tin]

Sponge Dough

200 gm bread flour

2.5 tsp instant yeast

120 ml water

•  Mix all ingredients into a soft rough dough.  Cover and leave to proof for at least 1-2 hours.

Ingredients for Bread Dough

120 gm bread flour
60 gm superfine flour

2 tbsp milk powder

5 tbsp sugar

1/4 tsp  salt

100 ml water or just enough to make a soft but not wet dough

30 gm butter
Topping
1 tbsp melted butter
some cinnamon powder combined with icing sugar
4 tbsp of blueberry pie filling 
Glaze - 1/2 egg yolk with 1 tbsp milk - mixed 

• Add all the bread dough ingredients [except water and butter] to the sponge dough.  Knead for awhile until well combined, then gradually add in water while kneading.  Continue to knead until a soft dough is formed.  Takes about 10 minutes then add in butter.  Continue kneading until soft, smooth, elastic and dough does not stick to the fingers [about 10 minutes on medium speed].
• Shape into a ball, coat with some flour and cover with a clean cloth to proof for 15 minutes or until double in size. Punch down dough.
• Divide dough into 4 equal portions.  Roll each portion into a square.  Brush lightly with melted butter, then spread a tablespoon of blueberry pie filling, sprinkle cinnamon and icing sugar.  Roll up tightly and cut into 4 pieces.  
• Arrange the rolled dough in a square baking tray line with parchment paper.  Repeat the same for the 3 portions.   Leave to proof in oven for about 30 minutes or until double in size.   
• Remove from oven and preheat oven at 190 degrees C.  Before baking, brush with egg glaze and sprinkle some sugar [if prefered].
• Bake in preheated oven for 20 minutes.  Remove to cool on rack immediately after baking.