Mix eggs, salt, sugar, sour cream, milk, baking soda, and baking powder. Blend in enough flour that the dough isn't sticky.
Pat out dough on floured board and roll to 1/2” thick.
Cut donut holes using a 1 1/2” cutter.
Prep a bowl with the confectioner sugar and set it aside for when the donuts are ready.
Heat cooking oil to 375°.
When donuts are lightly golden, turn with a slotted spoon and repeat cooking on the flip side. (it should take approximately 45 seconds per side to get the right golden hue)
Carefully remove donut holes from the fryer with a slotted spoon and place them on a paper towel to drain.
While still warm, toss donut holes in the confectioner sugar to coat.