Heat the milk in a small bowl till it's warm, but not hot and you can comfortably dip a finger in. Add the yeast and sugar, stir it around, then cover with clingfilm and set aside for 5 to 10 mins till frothy.
In the bowl of a stand mixer fitted with the dough hook, or in a large mixing bowl, combine the yeast mixture, salt and olive oil. Mix for a few seconds.
Add the flour and knead on medium speed for 3 to 4 minutes until the dough comes together in a smooth ball. If you a poke a finger on the top, it should slowly bounce back, that's when you know it's ready to rise. If you're not using a mixer, mix the dough in a bowl, then knead on a lightly floured counter for about 5 to 7 minutes.
Lightly oil the bowl you just used, then place the dough in it. Roll it around to coat all sides with oil. Cover tightly with clingfilm and set aside to rise in a warm place for 1 to 2 hours, until doubled.
Grease an 8" square pan. The cheese tends to stick, so greasing is important.
When the dough has doubled, punch it down to release the air, then turn it out onto a lightly floured counter or large silicone mat (for easy clean up). Roll or pat the dough out into a roughly 10 x 12 inch rectangle, making sure it's even all over.
Drizzle 1 tsp olive oil over the dough to prevent the sauce from making it soggy. Then spread the sauce in an even layer, leaving about half an inch border on all sides. Top with the grated mozzarella.
Starting at the shorter end, slowly roll the dough up tightly into a cylinder and place it seam side down. Slice using a sharp knife into 9 equal pieces. Some of the sauce may ooze out, making it difficult to roll the dough properly or cut it into even pieces. Don't worry about it, it all works out in the end!
Place each roll in the prepared pan, with the cut side facing up (see photos in the post above), leaving a slight gap to allow them to rise further, although if they do stick together, it's ok. Cover the pan tightly with clingfilm and leave to rise again for about 1 hour until puffed and doubled.
Preheat the oven to 180 C. Remove the clingfilm from the pan and bake for 30 to 35 minutes or until lightly browned on the tops and sides. Sprinkle the extra 1/3 cup mozzarella all over, and bake for an extra 5 minutes to let it melt.
Allow the rolls to rest for a few minutes, then using a sharp knife, cut each one out, enjoy the cheese pulls from the mozzarella on top and eat warm! Best on day one, but you can store them in the fridge for 3 to 4 days and reheat gently in the oven before eating. Happy bread baking!