Line 2 large baking sheets with parchment paper, and set aside.
Once the dough has risen, punch down to remove the air, and turn out onto a lightly oiled workspace.
Divide the dough into 16 equal pieces and shape into balls.
Top each dough ball with a little oil.
Cover the balls with parchment paper and a towel and allow to rest for 20 minutes.
Top each dough ball with about 6 g of softened butter.
Working with one dough ball at a time, spread the butter into the dough, and stretch the dough to form a rectangle.
If filling with nutella, spread 1 tablespoon of nutella over the rectangle.
Using the long side of the rectangle. roll the dough into a log.
Stretch and twist the dough to about 30 cm in length
Fold the dough in half, and stretch and twist until about 20 cm in length.
Form a ring and tuck the ends into each other.
Place onto a prepared baking sheet.
Repeat for each of the dough balls. You should have 8 plain and 8 filled (if filling)
Cover the rings with clean towels and allow to rise in a warm place for 30 minutes.