For the donuts:

1. In a medium bowl, heat the milk in the microwave until it is warm to the touch, for about 45 seconds.
2. Add in the yeast and give it gentle stir. Let the mixture sit until there is some foam on top, for about 5 minutes.
3. Using a stand mixer fitted with the dough hook, beat together the yeast mixture, the eggs, First Choice butter, sugar and salt until combined.
4. Add in about half of the flour and mix until combined.
5. Add in the remaining flour and mix until combined.
6. During the mixing process, you may need to stop the mixer and scrape down the sides. If the dough is too wet to handle, add in flour 1 tablespoon at a time.
7. Cover the bowl with a large kitchen towel, and leave it in a warm place to let it rise until it doubles in size, about 1 hour.
8. When the dough is done rising, pour it onto a well-floured surface and roll it to 1.5 cm thickness. Cut the donuts with a round cookie cutter .
9. Knead scraps together, being careful not to overwork the dough, and repeat the process of rolling it out and cutting the donuts.
10. Place the cut donuts on parchment paper, leaving room to rise between each one. (TIP: I place each donut on an individual piece of parchment paper, so it is easy to transfer into the hot oil for frying.)
11. Cover the donuts with a kitchen towel and let them rise in a warm place until they are puffed up, about 45 minutes.
12. About 15 minutes before the donuts are done rising, heat oil in a deep-fryer or large heavy-bottomed pot to 190°C. Place cooling racks on top of sheets of paper towels parchment paper, or line plates with paper towels.
13. When the donuts are ready and the oil is hot, carefully add the donuts to the oil, a few at a time without overcrowding your deep-fryer or pot.
    When the bottom of the donuts are golden, about 45 seconds, flip the donuts over using a spatula.
    Cook until the other side is also golden.
14. Remove donuts with a tong or slotted spatula, and place on the prepared racks or plates.
    Repeat with the remaining donuts, making sure to keep the oil at the right temperature.

For the filling:

1. Mix cinnamon and castor sugar together and pour on tray.
2. Cover each donut with cinnamon sugar.
3. Heat the First Choice Custard in pot over meduim heat.
4. Make a slurry with milk, sugar, vanilla essence and cornflour and wisk briskly into the custard untill the custard thickens.
5. Use the back of a teaspoon to make one hole in the donuts, then use a syringe or baster to fill the donuts with custard.