In a small saucepan over high heat, bring to a boil apple cider then reduce heat to simmer. Stir occasionally until reduced to 1 cup, about 15-20 minutes. Set aside and cool completely.
In a small bowl, combine sugar, 1 tablespoon cinnamon, and set aside.
In a large bowl, combine flour, brown sugar, baking powder, salt, baking soda, nutmeg and remaining 1½ teaspoons cinnamon.
In another bowl, whisk together butter, eggs and apple cider.
Pour mixture over dry ingredients and stir until just moist. Cover and place into the refrigerator until chilled, about 1 hour. Divide dough in half.
On a lightly floured surface, roll dough into 1/2-inch thick rounds and cut out rounds with a 2½-inch cutter or rim of bowl.
Heat vegetable oil in a large stockpot over medium-high heat to 375℉.
Working in batches, add the donuts and cook until evenly golden and crispy, 1 minute per side. Transfer to a paper towel-lined plate for 30 seconds, then roll warm donuts in cinnamon sugar mixture to coat.
Enjoy!
