01 -
Pour the apple cider into a medium saucepan and let it simmer gently over low heat until it reduces down to about ¾ cup. This should take around 30 minutes. Once reduced, set it aside to cool completely to room temperature.
02 -
Sift the flour, baking powder, baking soda, salt, cinnamon, and nutmeg together into a medium bowl. Set this mixture aside for later.
03 -
In a large mixing bowl, use a stand mixer to cream the softened butter with both the granulated and brown sugars until they're light and fluffy. Add the eggs one at a time, making sure each one is fully mixed in before adding the next. Scrape down the sides and bottom of the bowl with a rubber spatula as needed.
04 -
Pour in the reduced apple cider, buttermilk, and vanilla extract, mixing until everything is well combined. Gradually add the flour mixture and mix just until incorporated. Gently fold the grated apple into the batter using a spatula.
05 -
Line a baking sheet with parchment paper and set it aside. Turn the dough out onto a generously floured work surface—this dough tends to be sticky, so don't be shy with the flour. Use a plastic bench scraper to help fold the dough over and add more flour as needed before cutting.
06 -
Roll the dough out to about ½-inch thickness using a rolling pin. Lightly flour your donut cutter (about 3 ½ inches) and cut out as many donuts as you can, placing them on the prepared baking sheet. Try to cut them close together to minimize scraps.
07 -
Prepare another baking sheet by lining it with several layers of paper towels. In a large, heavy-duty pot, heat about 3 inches of canola oil to 375°F.
08 -
Carefully drop 4 to 5 donuts into the hot oil, being careful not to crowd the pot. Fry them for 1 to 2 minutes on each side until they turn a beautiful golden brown. Remove them from the oil and let them drain on the paper towels.
09 -
While the donuts are still warm, mix together the sugar, cinnamon, and nutmeg in a small bowl. Generously sprinkle this cinnamon sugar mixture over the warm donuts, coating them completely.