01 -
Simmer 2 cups apple cider in a saucepan over medium heat until reduced to about 1/2 cup, stirring occasionally to prevent burning. Let cool completely before use.
02 -
Combine flour, baking powder, baking soda, ground cinnamon, ground nutmeg, and salt in a medium bowl; whisk to blend evenly.
03 -
In a large bowl, beat softened unsalted butter with granulated sugar until light and fluffy.
04 -
Add eggs one at a time into the butter-sugar mixture, beating well after each addition. Stir in the cooled reduced apple cider, buttermilk, and vanilla extract until combined.
05 -
Gradually add the dry mixture to the wet ingredients, mixing gently until just combined into a soft, slightly sticky dough. Cover and refrigerate for at least 1 hour to firm.
06 -
Lightly flour a work surface and roll chilled dough to approximately 1/2-inch thickness. Cut out doughnuts and centers using a doughnut cutter or rings, reroll scraps as needed.
07 -
Heat 2 to 3 inches of vegetable oil in a heavy pot to 350°F (175°C), using a thermometer to maintain temperature.
08 -
Fry doughnuts in batches for 1 to 2 minutes per side until golden brown. Avoid overcrowding the oil. Remove with a slotted spoon and drain on paper towels.
09 -
Mix granulated sugar with ground cinnamon in a shallow bowl.
10 -
Toss warm doughnuts and doughnut holes in the cinnamon sugar mixture until thoroughly coated.