Place apple cider in a small saucepan, on medium heat. Bring to a boil, the reduce to a simmer. Allow cider to simmer for 15 minutes or until it has reduced to a ¼ cup. Remove from heat to cool.
Prepare the topping to set aside. Stir the granulated sugar, and cinnamon together in a shallow medium bowl. Save for coating warm donuts.
Remove stem and core from one JUICI apple, then chop into pea sized chunks. Set aside.
Preheat oven to 350 F (180 C) and prepare two of the 6 capacity donut pans with a light coating of baking spray.
Combine flour, baking powder, baking soda, and salt together in a medium bowl and whisk to mix.
Place brown sugar, egg, apple butter, and vanilla in a large bowl, then hand whisk to combine. Stir in the reduced apple cider until distributed evenly.
Add half of the flour mixture to the wet mixture and slowly whisk to combine. Repeat with the second half of the dry mixture. Fold in the apple chunks with a rubber spatula or wooden spoon to evenly distribute.
Spoon the thick batter into each donut cup about ⅔-3/4 full.
Place the donut trays on the middle rack of the oven. Bake for 10-12 minutes until the tops spring back with a gently press of your finger tip.
Place trays on wire cooling rack for about 2 minutes. Then, invert pans to release donuts directly onto wire racks.
Go ahead and coat these warm donuts with cinnamon sugar before cleaning pans and baking remaining batter. Totally optional, I just prefer to roll my donuts in cinnamon sugar while they are warm.
Place a warm donut in the bowl and twist, then flip to coat all sides in sugar. Repeat with remaining donuts.