Cue this question post lunch yesterday when I bought a regular sugared donut and wondered why there had to be a hole in the middle.
Lo and behold, my answers were found in the mythical acres of Google.
Quoting from this article from Wonderopolis:
A sea farer Hanson Gregory was probably the first “inventor” of donut holes as he realised deep frying the bread caused the sides to be crispy but the middle to be soggy and moist. To resolve this issue, a hole is cut thus the heat cooks the dough in the inner circumference evenly as well.
It was also potentially a way for bagel seller who sold these treats on a stick to have a hole to put a stick through.
On a side note, I’ve learnt from this article that most commercial donut holes are a lie and are just square or rounded pieces of dough deep fried and sold as donut holes.
Deception of the donut hole indeed.