01 - Preheat oven to 350°F. Lightly grease two standard donut pans (12 cavities total) with nonstick spray.
02 - Pour apple cider into a small saucepan. Simmer over medium heat until reduced by half, to approximately ½ cup. Let cool slightly.
03 - In a large bowl, whisk together flour, baking powder, baking soda, cinnamon, nutmeg, allspice, cloves, and salt.
04 - In another bowl, whisk together the reduced apple cider, melted butter, eggs, granulated sugar, brown sugar, applesauce, and vanilla until smooth.
05 - Add the wet ingredients to the dry ingredients and gently mix until just combined; avoid overmixing.
06 - Spoon or pipe the batter evenly into the prepared donut pans, filling each cavity about ¾ full.
07 - Bake for 10–12 minutes, or until a toothpick inserted into a donut comes out clean.
08 - Allow donuts to cool in the pan for 5 minutes, then transfer to a wire rack.
09 - For the topping, mix granulated sugar and cinnamon in a shallow bowl. Brush each warm donut with melted butter, then dip into the cinnamon sugar mixture to coat.
10 - Serve warm or at room temperature.