While the donuts are proofing, prepare the glaze by combining all the glaze ingredients and mixing together until smooth and a good consistency. If it's too thick, add more milk; if too thin, more sugar.
For chocolate frosting, add 3 Tbsp cocoa powder to the powdered sugar and increase the milk quantity. The cocoa will require a disproportionate amount of milk. Add liquid until it is a thinnish, easily spreadable consistency.
Heat the oil. Use a pot clip to suspend a probe in the oil in a heavy pot. (Don't fill the pot more than halfway.) Set the CehfAlarm high-temp alarm to 375°F (190°C) and the low-temp alarm to 350°F (177°C). Heat the oil over medium-high heat.
When the oil is hot and the donuts are ready, cut the parchment the donuts are on into squares using a sharp knife.
lift the squares one at a time and use them to slide/flip the donuts into the hot oil.
Monitor the oil temp as you cook 2 or 3 donuts at a time.
Flip them after cooking for 2 minutes. Cook another two minutes and remove them to a paper towel-lined tray.
Bring the oil temp back up and fry more donuts.
Once the donuts are cool enough to handle, dredge them in the glaze. Using chopsticks to lift and turn them will make it easier.
Serve the donuts while they are still hot and fresh.