1. Prepare the sweet stiff starter and use when it triples, about 7-8 hours at 27°-28°C.
2. Mix everything with standing mixer, except butter until the dough comes together and becomes strong.
3. Add butter in 2-3 times and knead until fully incorporated, and dough achieves window pane.
4. Bulk ferment the dough for 2 hours at 28°C.
5. Punch down the dough and split into 8 equal parts (approx 70g).
6. Round up each dough, leave for final proof at 28°C for 3-3 ~ 5 hours or until the dough rises 1.5x.
7. Indent the dough middle part with a rolling pin (you may dust the pin with flour).
8. Egg wash on the dough side then add the blueberry jam in the middle.
9. Place blueberries into the jam then sprinkle streusels.
10. Bake at 180C for 15-18 mins.
