There is/was a place called John's Donuts on San Gabriel Blvd that made better buttermilk dounts than Primo's. They called them buttermilk balls, I think. It was just a fist-full of dough dropped into the fryer. The dark brown crust was thicker than the conventional buttermilk donut, and kinda crispy ... but not oily. The crumb stayed soft and moist longer than most donuts because it was sealed inside the substantial crust. There was no buttermilk ball alike. Each one had unique nooks and crannies where the crust was extra crunchy.
Anyway, if John's is still around it might be worth a drive.