Ring doughnuts are made by joining the ends of a long , thin piece of dough into a ring or by using a doughnut cutter , which perfectly cuts the outside and inside shape , leaving a doughnut-shaped piece of dough and a doughnut hole from dough removed from the center . Ring doughnuts are formed by joining the ends of a long , skinny piece of dough into a ring or by using a doughnut cutter , which simultaneously cuts the outside and inside shape , leaving a doughnut-shaped piece of dough and a doughnut hole from dough removed from the center .