Heat apple cider in a small saucepan over high heat. Bring to a boil; reduce heat and simmer, stirring occasionally, until reduced to 1 cup, about 30 minutes. Let cool completely.

In a small bowl, combine sugar and 1 tablespoon cinnamon; set aside.

In a large bowl, combine flour, brown sugar, baking powder, salt, ground ginger, baking soda, nutmeg and remaining 1 1/2 teaspoons cinnamon.

In a medium bowl, whisk together melted butter, egg, apple cider, and sour cream until smooth.

Pour wet mixture over dry ingredients and stir using a rubber spatula just until combined and no dry pockets of flour remain- it should be a fairly thick dough. Cover and place into the refrigerator until chilled, about 1 hour.

Working on a lightly floured surface, roll dough into 1/2-inch thick sheet. Cut out rounds with a 2 1/2-inch cutter and use a small cutter to cut the donut holes. Place the tray of cut donuts and holes into the freezer while you heat the oil.

Heat vegetable oil in a large stockpot or Dutch oven over medium high heat until a deep-fry thermometer registers 360 degrees F.

Working in batches, add donuts to the Dutch oven 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. Serve warm and enjoy!