Pour the oil in a deep skillet or large saucepan. Heat over medium heat until hot.
Use a one-inch cookie cutter to cut out the center of each sandwich. Discard the center or fry separately.
Place the sandwiches in the hot oil, making sure not to crowd the pan. Cook one side for two minutes, then flip the sandwich and cook on the other side for two minutes. The sandwiches are done frying when each side is golden brown and crisp.
Transfer the cooked donuts to a paper towel lined plate and allow to cool.
Sprinkle powdered sugar over the top of each donut before serving.