Begin by adding your apple cider to a small pot and bringing to a boil. Reduce heat to medium and reduce until you have ½ cup of apple cider left (about 15-20 minutes).
Once the apple cider is reduced, let sit for 10-15 minutes to cool before using in your recipe. Once cooled, preheat your oven to 350F.
In a large mixing bowl, add the apple cider, sugar, apple sauce, oil, and vanilla. Whisk to combine.
Then add in the pastry flour, baking powder, salt, cinnamon, and baking soda. Make sure to add the flour first and then add the other ingredients on top. Then, use a fork to gently sift the baking powder, baking soda, and salt into the flour. Once sifted, mix everything together until a batter forms.
Spray the donut pan with a cooking spray or gently grease with oil. Then, add the batter to the pan making sure not to cover the holes in the center. The batter should make 6-8 donuts. Bake for 12-15 minutes until the donuts are baked through.
Remove the donut pan from the oven and carefully invert onto a drying rack (I like to bring the drying rack up to the pan and then flip it there to make sure the doughnuts don't fall apart). Let cool for 10 minutes.
While the doughnuts are cooling, prepare your cinnamon sugar topping by adding the melted coconut oil or butter to a small bowl and the cinnamon sugar mixture to a larger shallow bowl.
Very lightly brush each donut with the butter/coconut oil. Then, dunk each donut into the bowl of cinnamon sugar and swirl around until coated. Let the donuts sit for about 10 more minutes and then dunk into the cinnamon sugar mixture one more time(optional, but recommended). Enjoy!
Leftovers can be stored in a closed container at room temperature for 2-3 days or in the freezer for 1 month. For the best results, store between layers of parchment paper. Also, these donuts can technically be stored in the fridge for 3-5 days, but it will dry them out so I do not recommend it.