Carefully transfer the donut batter into a piping bag or ziplock bag. Pipe the donut batter into each of the prepared donut cavities in the donut pan. This should fill about ¾ of each cavity of the donut pan.
Cool the donuts in the pan for 5 minutes before gently taking them out of the pan and transferring them onto a cooling rack. Pour the powdered sugar into a clean ziplock bag. While the donuts are still warm, toss one at a time into the powdered sugar until well coated.