Pre-heat the oven to 175℃ (350℃).
Grease and line a fairly small loaf tin (mine was 23cm x 13cm / 9" x 5"). I don't line the whole pan, just the middle, which I leave with a little overhang, making it easier to remove the bread from the pan.
Roll out the dough to a rectangle of around 23cm x 30cm (9" x 12"), with a depth of around 1cm. Have the shorter edge facing you.
Whisk the egg well, and brush all over the dough (keep and leftover egg, and put to one side).
Mix the sugar and cinnamon and sprinkle over the dough, using your fingers to spread it evenly.
Taking the shorter edge (facing you) tightly roll the dough. Finish with the seam facing down.
Tuck the sides underneath to fit the pan you are using, and place in the pan. You can either leave the roll as it is (to create a rounder loaf) or press it down to fit the whole pan as I did.
Cover with a tea-towel and leave to rest for a further 30 minutes.
When ready, brush over the remaining the egg, and sprinkle with pearl sugar (if using).
Bake for around 20-25 minutes, then remove from the oven, and allow the bread to cool for a while before removing from the pan. Enjoy warm, or the next morning as toast.