In a 5 1/2 quart dutch-oven, or similar, heat up 1 quart (4 cups) of canola oil to 375 °F (191 °C)
1 quart canola oil
While the oil is heating up, separate out the biscuits and using a small biscuit cutter, cut out a hole in the middle of the dough and roll that cut out into a ball for the donut hole.
1 can of Pillsbury buttermilk biscuit dough
Once the oil has heat up to the correct temperature, gently drop the donuts, 2-3 at a time, into the hot oil and fry until puffed and golden on both sides, about 1-2 minutes.
Using a slotted spoon or spider strainer, transfer donuts to a wire rack covered with two paper towel layers to cool completely. Repeat until all donuts and donut holes have been fried.
While the donuts are still warm, toss donuts in a bowl of a sugar and generously coat them with granulated sugar.
1/2 cup granulated sugar
These are definitely best eaten warm and within a few hours of frying. They do NOT keep well. By the next day, they were super doughy and didn't taste good at all.
Notes
You'll want to keep your oil temperature steady at 375 degrees Fahrenheit. Using a candy/frying thermometer is the most handy in this situation because it just clips to the side of your pot.If you notice your oil getting too hot, cut the heat. If you notice it cooling down rapidly, turn up the heat or fry less donuts at the same time.