01 - In a small saucepan, simmer 1 cup of apple cider over medium heat until reduced to 1/3 cup. This should take approximately 10 minutes. Set aside to cool completely.
02 - Preheat oven to 350°F (175°C). Lightly grease a standard donut pan.
03 - In a large mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, ground cinnamon, ground nutmeg, ground allspice, and ground cloves until thoroughly combined.
04 - In a separate mixing bowl, whisk together the granulated sugar, light brown sugar, large eggs, melted and cooled unsalted butter, the reduced apple cider, whole milk, and pure vanilla extract until the mixture is smooth and well incorporated.
05 - Gently pour the wet ingredients into the bowl containing the dry ingredients. Mix until just combined, taking care not to overmix the batter.
06 - Spoon or pipe the donut batter into the prepared donut pan, filling each cavity approximately 3/4 full.
07 - Bake in the preheated oven for 12 to 15 minutes, or until the donuts are golden brown, spring back when lightly touched, and a toothpick inserted into the center comes out clean.
08 - Allow the baked donuts to cool in the pan for 5 minutes before carefully transferring them to a wire rack to cool completely.
09 - In a small bowl, whisk together the powdered sugar and ground cinnamon. Gradually add the apple cider, one tablespoon at a time, while whisking, until a smooth, pourable glaze consistency is achieved.
10 - Dip the tops of the completely cooled donuts into the cinnamon glaze. Place them back on the wire rack to allow the glaze to set before serving.