Proof the yeast
Take out approx. one tablespoon of your all-purpose flour and mix it with an equal amount of sugar. Add a bit of the milk to create a soup in which you dissolve your yeast. Set aside for a few minutes until the mixture is bubbly.
Make the dough
Meanwhile, mix the remaining flour with cornstarch and sugar. Stir in the bubbly yeast and the remaining ingredients, adding enough milk to make a sticky but still elastic dough. If it comes out too dry, you may add some more milk. If it's too sticky to handle, you may add some flour, but try to restrict adding more flour as much as possible.
Turn the dough onto a lightly floured counter or kneading board and keep kneading the dough for about 10 minutes. If you have a kitchen machine, use it. This dough is way softer and slightly stickier than normal bread dough, so it's more challenging to handle. Once you've finished kneading, cover the dough with a clean, moist towel and let rise in a warm place until it has doubled in size (about half an hour).
Cut out donuts (or shape them!)
Cut out small squares from your baking paper and set aside. To cut the donuts, I used a cookie cutter with about 6 to 7 cm diameters (2.3 to 2.7 inches). If you have a donut cutter, feel free to use that, of course. If you have neither, you can use the top side of a drinking glass and just cut out rounds instead.
Roll out your dough on a floured surface to about 3/4 cm thickness (0.3 inches). Cut out donuts and put on the paper squares. You will notice while handling that the dough is much stickier which is why we're using baking paper. If you want to be extra fancy and go by the ingame image, you can roll small bits of dough into a ball and align them in a circle on the paper square. It's better to make them bigger, so they become less fragile. If the balls aren't sticking well to each other, you can use some water as an adhesive.
Once you've cut out all the donuts, it's time to heat the oil in a deep frying pan or deep fryer. If you have a thermometer, go for 170°C (approx. 340°F). If you don't have one, you can test the heat by dipping a wooden chopstick into the oil. If tiny bubbles appear around it, the oil is hot. Never under any circumstances leave the room while you're heating oil! It catches on fire quicker than you think!
Fry the donuts
Using a slotted spoon or a skimmer spoon, carefully immerse the donuts with the paper into the hot fat. Depending on the size of your donuts and the size of your pan, you can fry up to 4 donuts at the same time. Wait for about one minute, then gently pull the wax paper from the donut with tongs and discard it. Fry for about 2 more minutes or until underside is slightly brown then carefully flip it. Fry for another 3 to 4 minutes until brown as well, then transfer the donut onto a tray lined with baking paper (to soak up excess fat). Repeat with the remaining donuts.
Decorate these beauties
Once they are cooled off, melt your candy melts according to the package OR mix the confectioner's sugar with the milk until you get a thick paste. Add gel food coloring and mix. Dip the donuts in the glaze. At this point, you can add sprinkles or whatever you want onto the wet glaze before it is set. If you are using chocolate, chop the chocolate into chunks and melt over a water bath, stirring constantly. Dip the donuts in the chocolate and let it set for about half an hour. Happy Starlight!