In a large bowl, combine the warm milk, a tbsp of sugar and the yeast, let it sit for 10 mins or until it blooms (appearing foamy on the surface)
Add in all other ingredients into the milk mix, use a stand mixer with a dough hook, and begin mixing on low speed for 5 minutes. Increase to high speed and continue mixing for 3 minutes.
Transfer to an oiled surface and knead by hand for 1 minute. Form a ball and place in the bowl, cover and leave to sit in a warm place until it has doubled in size, this should take anywhere between 1-2 hours.
Transfer the dough to the oiled surface, use a rolling pin to roll out the dough to an inch thickness. Use a donut cutter to cut out the donuts, mould into a perfect ball and place on a lined sheet.
When the dough balls are all laid out, cover and let it proof a second time for 30 minutes while you heat up your oil for frying to a temperature of 360℉-370℉.
Begin frying the donuts in batches, it is important you don't overcrowd the pan. Flip over when the donut has browned slightly.
When the donuts have browned nicely on both sides, pack them out and lay them on a rack to drain.
Mix the cinnamon and sugar together. Toss in the donuts until they are fully coated with the cinnamon sugar.