Add all the dough ingredients to the bowl of a stand mixer and mix with a dough hook on slow speed for 2 minutes. Increase to medium speed and mix for a further 6-8 minutes until the dough comes away cleanly from the side of the bowl.

Form the dough into a ball and place it into a floured bowl. Cover and let rise for around 45 minutes or until double in size.

While the dough is rising, make the cinnamon filling by beating the butter, brown sugar, and cinnamon together.

On a lightly floured surface, roll the dough into a large rectangle approximately 12x16 inches.

Spread the cinnamon filling over the entire surface of the dough.

Fold the dough into a trifold, then slice it width-ways into 12 strips each roughly 1.5 inches across. Cut twice down the length of each strip to make three strands.

Braid the three strands together and roll it up length-wise. Place each bun on a lined baking sheet.

Cover the buns with a tea towel and let rise for 1 hour or until double in size.

Preheat the oven to 350°F when the buns are close to being done rising.

Brush the buns with the egg wash and bake for 20-25 minutes, until golden brown.

Let cool for 5 minutes before serving and sprinkle with powdered sugar if desired.