Flatten the dough into a board by using a rolling pin (about 45 cm x 35 cm). Make sure the dough is even in thinness. If the edges on the long side are too uneven, trim them with a sharp knife of dough cutter. Do not worry if the short ends are uneven, you would trim these sides later on.
Spread the cinnamon filling evenly on the dough. Keep about ½ inch of the dough (on both long sides) without the cinnamon filling.
Roll the dough tightly into a log (roll from the long side). Trim the remaining uneven sides.
Cut the log into smaller and equal portions – about 3 cm each portion. (This recipe normally yields 14 to 16 buns).
Place each bun into a baking tray with a baking sheet. Cover with a clean kitchen towel and set aside for 1 to 1 ½ hours (until the dough has become slightly puffy). Remember to give the buns enough space in between since they will expand once cooked.
When the buns are ready, preheat the oven to 200°C (375°F).
Brush the buns with the beaten egg. Sprinkle each bun with pearl sugar.
Place baking tray in the middle of the oven for 17 to 20 minutes.
Serve. Sprinkle more pearl sugar, if desired.