Preparation
In a small saucepan, bring the cider to a boil over high heat. Cook until reduced to 1/2 cup, 8-10 minutes. Let it cool completely. In a bowl, sift together 3 1/4 cups flour, sugar, baking powder, baking soda, cinnamon, nutmeg, and salt. Add in the butter and beat on low speed until the mixture forms fine crumbs. In another bowl, whisk together the buttermilk, eggs, 1/4 cups of the reduced cider, and the vanilla until combined. Add the buttermilk mixture to the flour mixture and mix until soft dough forms. Turn out onto a very well-floured surface and knead until smooth, adding more flour if needed (it will be needed!). Line a rimmed baking sheet with parchment flour and sprinkle some more flour onto it. Pat the dough onto the parchment to about 1/2 inch thickness (thinner if you’re making mini donuts like I did). Freeze for about 15 minutes until they firm up.
Pour oil a couple inches of oil in your skillet (I used my Lodge cast iron) and heat on med-hi to 350 F. (You’ll need your deep frying/candy thermometer!). Set a large wire rack over another baking sheet and place it near the stovetop. Using a donut cutter (or juice glass, whatever) cut out donuts and holes (I used the tube that holds my vanilla beans). You can reroll the scraps and use them.
Using your spider strainer, drop 2-3 donut in the oil at a time. Or, if you’re brave like me just drop them in there. The recipe I used says 3 minutes, but mine fried up in about 30 seconds. Turn them once at the halfway point; when they’re a nice, lovely dark golden brown they’re done. Again, your spider strainer will be your best friend. Transfer to the cooling rack and then let them cool completely. Don’t forget to the fry the donut holes too!
To make the glaze, bring the remaining 1/4 cup cider reduction back to boil, then whisk in the the sifted powdered sugar. Remove it from heat and let it cool just a little. Dunk each donut in the glaze and let the excess drip back into the saucepan. Return to wire rack till the glaze is set.