Pour the apple cider into a small saucepan. Bring to a simmer over medium heat and reduce by half, until it measures about 1/4 cup. This should take 8-10 minutes. Set aside to cool slightly.

Using a 1-inch round cookie cutter, cut a hole in the center of each Hawaiian roll. Keep both the donuts and the donut holes. Melt the unsalted butter in a small microwave-safe bowl or saucepan.

In a shallow bowl, whisk together the granulated sugar and ground cinnamon for the coating. Set aside.

Once the reduced apple cider is cool enough to handle, whisk it together with the sifted powdered sugar in another small bowl until a smooth glaze forms. Adjust consistency with a tiny bit more powdered sugar if too thin, or a few drops of water if too thick.

Preheat your air fryer to 350°F (175°C).

Brush the tops and bottoms of the Hawaiian roll donuts and donut holes lightly with the melted butter. Work in batches to avoid overcrowding the air fryer basket.

Place the brushed donuts in a single layer in the air fryer basket. Air fry for 3-5 minutes, flipping halfway through, until golden brown and slightly crisp. Donut holes will cook faster, usually 2-3 minutes. Remove and place on a wire rack set over parchment paper or a baking sheet.

While the donuts are still warm, dip each donut (and donut hole) into the apple cider glaze, ensuring both sides are coated. Let any excess drip off.

Immediately after glazing, roll the donuts in the cinnamon sugar mixture, ensuring they are evenly coated. Place them back on the wire rack to set slightly.

Serve warm and enjoy your homemade Apple Cider Hawaiian Roll Donuts!