If using active dry yeast, in a small bowl mix the sugar and yeast in the lukewarm milk and let the yeast activate for about 15 minutes until foamy. If using fresh yeast, crumble the yeast in the flour before starting mixing the dough.
To a mixer with a dough hook, add all the dough ingredients. Mix on a low speed for about 5 minutes, then increase the speed to medium and mix for a further 12 minutes until the dough comes away from the bowl. If you are kneading by hand, knead until you get a soft and smooth dough, after about 15 minutes of kneading.
Form the dough into a ball and let it rest in a warm place covered for an hour until it doubles in size.
For the filling, mix the butter, cinnamon and brown sugar together until a paste is formed, and set aside.
On a floured work surface roll the dough into a rectangle, roughly 40 x 30cm.
Spread the cinnamon sugar paste over the dough.
Fold the dough lengthways, by closing the bottom half of the dough first, and then fold the other half on top. Cut widthways into 12 strips about 3 cm each. Cut each strip lengthways, not all through, into three.
Braid each strip and roll on itself. Place in a muffin tray or silicone muffin cups. Don’t worry if it is messy, that is how it should be.
Cover the muffin tray loosely and let sit for another 30 minutes.
In the meantime, preheat the oven to 200°C.
Brush the buns with the egg wash and bake them for about 20 minutes, until golden.
Before transferring the buns to a cooling rack, let rest for about 5 minutes on the baking tray.
Store rolls in an airtight container. These sticky cinnamon buns can be enjoyed at room temperature or slightly warmed up before serving.