Add the 2 1/2 cups of apple cider to a medium sauce pan. Heat over medium heat.
Let simmer until it thickens and reduces to 1/2 cup. This will take probably about 30-40 minutes. Check it around 30 minutes and see how much is left, try to get as close to 1/2 cup as possible. It will look darker in color and thicken slightly into a more syrupy consistency.
Once done, measure it out, if you have exactly 1/2 cup, perfect! If you have slightly less, just top it off with a splash of regular apple cider until you get 1/2 cup.
Set aside to cool for 10 minutes.
Meanwhile, preheat the oven to 350 degrees. Generously grease and lightly flour 2 six cavity donut pans and set aside.
Whisk together all wet ingredients until combined.
Whisk in the dry ingredients until well combined, it will be thick.
Transfer to a piping bag or large ziplock bag and cut off the tip.
Pipe into the donut pan, you'll end up using about 1/4 cup per donut.
Once all batter has been used, add to the oven and bake for 9-14 minutes or until a toothpick comes out clean.
Let cool in the pan for a few minutes, then flip onto a wire rack. If they aren't falling out easily, carefully take a knife and slice around just the edges of each donut, then try flipping again.
Melt the 1/2 cup of butter in a shallow bowl and then whisk up the sugar and spices in another shallow bowl.
Dip each donut in the butter, then the sugar and spice mixture. I like to coat it really well in the sugar, but just a few flips on each side is fine.
Repeat with all donuts and enjoy!