Add apple cider to small saucepan
Bring to boil over medium high heat and cook until reduced to ¼ cup, about 10 minutes
Cool completely
Preheat oven to 350 degrees F
Coat donut pans with non-stick cooking spray
In a large bowl, beat sugar and butter until combined
Add eggs and mix until well combined
Add buttermilk and reduced apple cider and mix until well combined
In a medium bowl, whisk together flour, baking powder, baking soda and spices
Add dry ingredients to wet ingredients and stir just until combined
Fill donut pan about ½ full ** see notes
Bake for 10-12 minutes or until lightly browned
Cool on wire rack for 5 minutes
Remove from pan
Combine cinnamon sugar coating or glaze in a medium bowl ** see notes for glaze
Melt butter in microwave safe bowl and cool slightly
Dip donuts in cooled butter and immediately coat both sides with cinnamon sugar mixture and set on a wire rack
Serve warm or room temperature
Store leftovers in airtight container