I think the problem is probably due to the texture of the dough and the lack of kneading in my case. I used a spatula and hand to knead the dough instead of using a food mixer.
The texture of the finished roll is good.
Once I get myself a food mixer, I'll try the cinnamon roll recipe in my previous blog to see if the shape of the rolls has improved.
For the filling, this time, I just mixed 60g brown sugar and 15g cinnamon powder in a bowl by using a fork to stir them all together. Then, I brushed 50g melted unsalted butter on the flattened dough. I sprinkled the sugar-cinnamon mixture on the flattened dough before rolling it into a roll. This amended process helped the filling easily distributed and stuck to the flattened dough.
Below are the photos of my second attempt on the cinnamon roll recipe:
