To make the doughnuts: Sprinkle some flour on your work surface. Roll out the tube of dough but don't separate it. Fold it over along the middle seam. Using a biscuit cutter or a glass, cut circles out of the dough at the widest point of each triangle. Use a smaller circle to cut out the donut hole. Scoop up the scraps of dough, reshape them into a ball, and roll it back out to the same width as the original square. Cut more doughnuts out. You'll end up with 7 doughnuts per tube of dough if you're using a 3 inch diametre cutter.